This is one of the best mechanic videos I have ever seen. Every step is explained, all the parts and pieces are described, the functionality of the engine and components are relayed to the viewer. Thank YOU for taking the time to do this. I wish more mechanic videos were this great.
Oh man, you did more than just save me money, you gave me CONFIDENCE!. I just successfully fixed my 9.8 Evinrude (it's a Tohatsu engine, really) after watching your video. My motor died while out 2 days ago - and because it's spring all the shops are saying it's 3-4 weeks before they can even look at it. I changed out my gas first, tried Seafoam treatment but no luck. So, based on your video, I took the Evinrude carb off (it's pretty much identical). I followed your cleaning directions and re-assembled. Pumped the gas and she started 2nd pull ! And is now purring like a baby. I've never touched a carb in my life until today. THANK YOU.
I have had my boat/motor for about 5 years purchased lightly used. It started running rough and then not at all last season and has been parked since. I recently have wanted to use it but have no mechanical knowledge and searched for about 3 months for explanation’s to my issue with little answers leading to the carb, but no good step by step how to on fixing it. I was communicating with a local mechanic and set to drop it off in the next couple days, when I came across your video. Your well executed very easy to follow step by step vid gave me the confidence to do the job myself. Thank you so much for the knowledge and confidence you provided and God bless you!!
This was a very helpful video for me. The one thing that I’ll add is this (which I discovered while cleaning my carburetor) I started off by using starter fluid rather than carb cleaner to clean the parts. The first time I took it apart, I removed the gasket between the bowl and the rest of the carburetor and I had no problems fitting it back in. The second time I pulled it apart, I was using carb cleaner. Unlike the starter fluid, carb cleaner caused both my rubber gloves and the rubber gasket to expand. In order to fit the gasket back into place, I had to clean all of the carb cleaner off from the gasket and wait a few minutes for it to shrink back to normal size.
Dear Technician, thank you very much for this detailed and explanatory tutorial. With your step-by-step verbal and visual guidance I confidently disassembled, checked, cleaned and reassembled my Mariner 9.9's carburetor and gained an insight into its functioning mechanism. My motor is running smoothly again owing to you. Warm greetings from Mugla (Milas), Turkey.
I gotta pull mine back apart. Thought I cleaned it good, but I did not take the jets out and clean it. Put it back together and still did not run. This is the only video I watched that even took the jets out. Thank you👍
I'm in the middle of this right now, frustrated as hell, took a break and found your video. This gotta be the most informative video I've ever watched. Bravo sir
I also thought the float might be stuck in the open(down) position but that was not the case. I disassembled the carb and cleaned it as per the video - some clogging in the high and low speed jets but gave both a good cleaning. I really think pumping the bulb rock hard forced too much gas to flow and stalled out the engine. After reinstalling the cleaned carb and two pulls on the rope, she started right up on the third pull and runs like a charm, even at idle. I would not have attempted this repair without this video. The first I could get in for a repair was one month away and goodness knows how much money. I hope that this mechanic and his team will feel really encouraged do more videos. They are providing an amazing service. Sam
Thanks Rowintel for this outstanding video. It gave me, a novice mechanic, the confidence to dive in and clean the carb on my 8hp 4 Stroke Merc which was running rough or quitting at idle and unusable for trolling. The carb was indeed dirty and I cleaned it per your instructions. In the process, I learned how carbs work. After putting it back together the engine started easily and purred like it should. The idle and mixture adjustments shown at the end of the video were invaluable. Fortunately, the brass plug for the mixture adjust screw had already been removed so I didn't have to deal with that drill out. Your background explanation and then step by step explanations exemplify what good how-to videos should be like. Well done and Thank You!
Thanks dude! A friend sunk my boat and the 9.9 merc was under water for a month before we got her up. I had no problem at all getting it to run again, but it would not run right. I knew it was the carb but had never taken one apart before. Using your excellent video here I took it all apart, cleaned, put back together in one hour. Motor started right up and runs great now. I was all set to spend almost $300 to have the local shop put a new one on. I thank you many times over for your excellent instructions. You did an excellent job.
Thank you SO much! Not only did your video teach me what I needed to know to fix my Mercury 9.9 kicker, which would not idle at all, but now, that particular problem will never cancel another boating event, like it did yesterday. All I needed was carb cleaner, two blade screwdrivers, rags, a 10 millimeter socket and an extension. I also used a guitar string which fit through the idle jet nicely and removed a stubborn piece of debris. I totally appreciate you sharing your knowledge. From now on that list of tools is on my sailboat.
Own a 15hp mercury and last weekend it started great but then stalled out. Removed cowl and saw standing gas in the bottom of the housing. Cranked her over and gas poured out the bottom of the carb. This was after I had pumped up the primer bulb to rock hard as fellow at boat ramp suggested. Pulled the start cord again and motor ran briefly but rough. I inspected the 2 plugs and both were badly flooded. I let it sit for about an hour, pulled the cord and she again ran briefly but rough. When I got the boat home I cruised You Tube and suffered through several abysmal videos on carb cleaning - no tripod, horrible sound, terrible lighting - one was even on a boat and was hand held - I almost got sea sick. Your video is clean, well organized, great lighting and pretty good sound. I think your use of the go pro for closeups was great. I followed right along with your video in little chunks and eventually finished my carb overhaul. I get to try it tomorrow morning. Sam
Thanks, my motor had sat idle for a couple of years. I thought that allowing it to run out of gas by disconnecting the fuel line would prevent carb problems. It started after a lot of rope pulls but acted like it was starving for fuel. I replaced some components of the fuel supply system but didn’t help the prob. Checking with mechanic he thought it could be the carburetor and he could get to it in about 4 weeks and would cost $250 to $300. I watched your video and followed your instructions and it is running great. Starts first pull now and responds perfectly to the throttle. Great video. Thanks a lot.
The author's extra comments helps compensate for me not having anyone to help me. For example the brass/aluminum and stainless steel aluminum helped me. Also, confronting the reality of screw ups by telling the cost of both screws and carbs, helped us face the reality that 'screw' ups happen.
Great video and tips! Gave me the nerve to fix my 9.8 4-cycle Tohatsu which started fine and would idle fine; however, it would shut off when throttled. Every 2-3 years I've had to take it to repair shop for similar problems - costing from $79-125 plus. Bought a can of carburetor cleaner for less than $4 and spent an hour or so carefully following you video. Removed, cleaned thoroughly, and reinstalled - started right up and ran perfectly! Thanks!
Thanks for the video. I have the TOHATSU MFS 8 that would kick over but not stay running. Felt it wasn't getting fuel and was hoping to find someone on TH-cam showing how to remove and service the carburetor. Easily removed and took apart the carburetor, thanks to your video. It was a mess and after a good cleaning runs awesome. Thanks again
Had trouble with poor idle performance. Followed this process and saved what was quoted as an $800 repair job. Engine ran just perfect without do the drilling out of the idle adjustment step. Thanks for the detail.
This was the best video out there. Watched it twice and went for it. So now my 9.9 is running like better than Dillinger after a bank robbery lol. Thanks.
This was just the video I was looking for. Good job explaining the procedure - Your voice is easy to understand. I was hesitant to clean my 15hp Merc Prokicker. The motors are surprisingly similar. Thank you for a great lesson.
I ALMOST gave up on trying to learn how to do this. Thank you SO much. I watched so many useless videos where the author just assumed I knew how to do so many things. THANK YOU!
Thanks for this video, watched it while I tore my carb apart on the bench, very concise and went from non running pro kicker to an engine that purrs like a kitten and started first pull.
Great vid. I have the same 9.9 except 07' model. I had to clean the carb the other day and ever since it wants to die when I shift it into gear...I'm thinking it's the idel screw now that I've watched your vid. Great vid! Very in-depth and helpful.
Excellent Video and content. I like that you know the parts of your carburetor and you where very thorough with details. Fixed my 9.9 carb issue. Clogged low speed jet. Symptoms where would not run with closed choke. Gratitude.
Bought a 9.9 Merc brand new 2.5 years ago. Not 50 hours of run time after break in, it would either stall at mid throttle cruusing or stall coming off the throttle. Dealing with the dealership repair (under warranty) has been a nightmare (6 trips..long waits). Last trip was to another dealer...they actually got it running right. Said carb was dirty. That was about 3 running hours ago (two short trips) and I'm back to square one. I'm going to follow your instructions to see if i can get it running. BTW, this engine has never seen one drop of ethanol and i run the carb dry every time i get her home. Never buy a 9.9 Mercury.
OUTSTANDING, I cleaned the carb reinstalled it and it ran fine. Late in the day I decided to run it again and it wouldn't idle. I took the carb off again and it was clogged again. fuel line and or filter had junk in it..
Yes great video, I been having trouble starting my 5 year old Tohatsu 9.8, changed plugs and fuel filter, once I got it stated I seen gas coming out top of carb, no hose. I'm thinking the float is stuck. I would never remove the carburetor but I will now after watching your video. Thanks
@ 22:00. When putting that cover back on, I’ve discovered a small black gasket from someplace inside there. Does it (gasket) go on the bottom side of the spring where it rest in the fuel line connect, or does it sit at the top, between the plunger and the spring? Thanks.
Fabulous explanation. Unfortunately on reassembly I broke the choke into carb black connector piece which has been causing other issue. I realized I could start it in gear override so all good there. Critical is black piece must be turned to correct no choke position. The other day while running black piece somehow shifted on its own and caused breakdown. Not knowing the issue I rowed 1.5 mile back to boat. I discovered this was the cause so decided to take out all the extra linkage parts and unfortunately took out linkage end connection piece with big spring behind it , oops!!! I am now unsuccessfully trying to reassemble that piece and cannot figure out the whole spring dynamic. I see one end goes into a little hole in carb. It appears other end goes against a part to keep it turned counter clockwise. Unfortunately cannot figure out how to do it or if I am correct. Wish I could show a picture. I have Mercury 8 ho 2015. Thanks.
Great Video, it would be good if you changed the Title to 9.9 Mercury, Tohatsu and Evinrude Caburator Cleaning/rebuild. I've owned both, a 2004 Tohatsu 9.9 and 2017 Evinrude. The engines are almost exactly the same, all made by Tohatsu. Great motors, but carbs need regular cleaning. I think a lot more people could benefit from your video with a little title adjustment. The Tohatsu and Evinrudes don't have the accelorator pump but I can see where it would of been as the carburator casting has everything for it.
Very nice video. Gonna try air/fuel-mixture screw on my Suzuki df15, that refuses to start. It starts eventually, but it takes way too long to be healthy. Carb has been cleaned twice now, but I haven't drilled out the mixture screw, now I'm Confident I can do it though very basic skill and Tools. Thanks man //Sweden
ROWINTEL.COM Allready installed new plugs in my first effort to get it running, nevertheless, it runs very well now. The mixture screw was way too lean, only about 3/4 out, so I set it to 2 and 3/4 (specs say 2 and 7/8)Thanks alot, really nice how you can help me from halfway round the World.
Hi, thanks for the video . My engine, works fine, but twice stalled after going full power for 10 or 15 minutes. After a while it will start again and work perfectly. Also it does throw away some small amounts of fuel to the water after shutting it of. Sounds like flooding of the carburator, perhaps stuck float . Any chance of solving it without dissasembling thw whole thing ?
Great tutorial but a suggestion. You have to organize your shop and keep it organized. Shelves on the outside walls, a bench, a steel table and tool organizers. You’ll find you finish projects much faster.
thanks got a 02 merc 15 hp 2 stroke pull start. will not start but a tiny spray of starter fluid and she starts right up but dies. I figure it might had been the needle valve gonna crack it open this weekend
Great video,mine is leaking fuel from what you did not take apart,the plunger that gives extra fuel when throttling up ,Iam getting a plunger diaphram for it. Am hoping take care of my leak
Thanks for the superb instruction - I followed along easily and saw improvement when I accelerate quickly. One thing that remains a struggle on my 4 stroke merc 9.9 is cold starting. Once started, it starts first pull, all day long. It is difficult to start without starting fluid and even more difficult to start without using the throttle only button and speeding up the throttle pretty high. I would really appreciate any suggestions you may have.
Did all but the main jet on my 9.9. That would not come out at all! Now to tune it to see if we can't fix the problem of stalling when going back to idle from a speed run.
Great Vid man i got a 15 hp merc its maybe a year or two old and im havng problem with high idle so shifting from nuetral to forward and vise versa is pretty violent. i realize i neeed to adjust the idle adjustmentment and mixture screw and mess with those next time on the water but im having trouble finding which screws are which, if you get this maybe you could post a pic with the idle screw circled and the air fuel mix screw circles too thanks.
Kyle Herrin I'll try to get a pic for you, but they are quite different. The idle adjustment screw (rpm adjustment) will directly contact the throttle plate and the screw head is parallel with the tiller (the screw head is aimed to the back of the motor), also the idle adjustment screw will have a spring wrapped around it. the idle adjustment screw will probably have to be backed out on yours to lower the RPM when shifting. You can see the screw with the spring at 29:29 in the video. The air/fuel mixture adjustment screw is perpendicular to the tiller (faces the port side of the motor) and is nestled behind that brass plug you'll have to drill out (may have already been drilled out), also it is usually a flat head where the idle RPM screw is a Philip's. 29:29 in the video shows the screws pretty well. On mercs there is another screw that is connected to the arm on the choke lever (this screw contacts the throttle plate when you pull the choke out). This screw has no impact on how the motor runs when the choke is pushed in, it just opens the throttle plate slightly when the choke is pulled out.
thanks, on top of the idle problems i just came to find out that the silver bar the connects the choke to the carb and the handle throttle to the carb is bent..more specifically the one that connects the throttle on the hand throttle to the actual carb. Does anyone have a part number or a name for this part? u can see the part inbetween you right thumb and index finger in the still of the youtube video
Devin: It sounds like your pilot jet is clogged. With the low quality fuel with ethanol we have today if it sits in the float bowl for very long it will evaporate and leave a gummy residue in the jets often clogging them. It is a common problem on carbureted motorcycles. Pull the float bowl and look at both the main and pilot jets. I bet you will find at least one of them clogged. When finished using the motor, disconnect the fuel hose and let it idle until it runs out of fuel in the bowl and the engined stops. Then it is empty and won't gum up the jets.
great video! On the low speed/idle jet is the hole that goes through the middle supposed to be the same size all the way through? I can blow through it and I can see a very small bit of light through it, but I can't send a small piece of wire all the way through. It goes part way in then hits up against something. Should I get a 32nd drill bit and drill through it?
Hi! My engine starts hard and runs rough when it starts. It shuts off multiple times and does react bad when giving it gas. However, once it runs a few minutes, the engine runs fine and picks up well when giving gas. Any idea what could be wrong? Thanks in advance!
Hi, i have a late model 9.8 tohatsu, it seems identical to the mercury. Can you do a video on how to change the timing belt. Not quite sure how to get the crankshaft pully off. Thanks
HI, I have the same engine as you but where I connect my throttle lever from the carb to the wheel, the wheel rotates and has a decent amount of play in it without me turning the throttle. Does the nut that holds the throttle pulley need to be tightened? It means my throttle will only engage when I'm almost at full power, in both reverse and forward, making small adjustments in power pretty much impossible. Thanks!
Hi super great video . I did exactly what you do in this video but my problem ... The motor still on high revolution it doesn’t go to throttle speed. Even if I unscrew the gas screw it still too high ... What could be the problem ? Thanks in advance !
great video! can the mixture screw inside the brass plate unbalance itself . I believe my outboard is suffering from that which gives its a poor idle and also dies on me after 10 seconds of throttle
The mixture screw will not necessarily "unbalance" itself, however dirt, corrosion, varnish, etc. can restrict the orifice for the idle mixture (restrict fuel flow) over time. The motor uses so little fuel at idle that a sufficient amount of fuel may flow into the intake to start it, but not keep it running. Removing the brass plug, and unscrewing half turn at a time (wait 10-20 seconds of running time between turns to give things time to adjust) should fix that problem. As a long term solution, use ethanol free gas that is no more than six months old, and use the recommended amount of SeaFoam fuel additive to help stabilize the fuel and clean out any gunk that is in there. Good Luck!
One more question, i took off the lower unit to change the impeller but now i feel as if when i pull start it it slips. i did put grease but i made sure not to put it on the top of the shaft just around it , do you think i put it in wrong? i didn't know moving the prop would put it back in place, so i just pull started it slowly until it fit right in. it pees faster and cooler, and all the gears are operating to their function. however, would that be causing any problems in reference to it dying on me.
fje137 Really shouldn't cause any problems with it dying. If it is a salt water motor with extensive corrosion, then all sorts of weird things can happen (i've seen water being pumped into the intake, and high exhaust pressure block water flow, things that shouldn't happen if corrosion hadn't eaten away at the engine block and water lines). Greasing the splines on the drive shaft at the top is a good thing to do and should never cause slipping. Those splines are pretty heavy duty and as long as you have a 1/4" or more engaging and there is no obvious signs of worn down splines (i've never seen those particular splines slip) you should be fine. Check how much engagement you are getting by rotating the prop by hand with the lower unit in reverse (or forward) and slowly slide the lower unit back up onto the motor, note when the splines start to grab into the crank of the motor. most likely what you are feeling is the pull start mechanism slip (easy to replace and they do wear out). To confirm, bypass the neutral start lock-out mechanism, remove the kill switch so the motor won't start (maybe remove the spark plug wires too), and put the motor in gear, when the cord comes out the motor should turn and also turn the prop, if the flywheel on top of the motor is turning but the prop is not, then you do have some weird issue going on with the splines slipping on the driveshaft (this is pretty unlikely though)
Rowtel, I was wondering if you had any thoughts about gas octane. In the Midwest we have 10% ethanol. Someone recommended using 91 or 92. I’m wondering what your thoughts are. Thanks!
I own a 15hp, 4 stroke Mercury outboard, 1999. It will not run at idle. I can get it to idle briefly by giving it full choke. I thought this indicated not getting gas at idle. I followed along with your video and got to where you remove and cleaned both the high speed and the low speed jets. I got the brass high speed jet out, cleaned and replaced but I could not get the low speed jet out - I could get it unscrewed but was unable to get the actual brass jet removed for cleaned. I tried tapping with the carb upside down but the jet would not fall out. I gave it a good shot of carb cleaner and will let it sit overnight and try again in the morning. Any thoughts why the jet will not come all the way out? Sam
Any advice on removing the main jet that just "falls out?" Mine is stuck good and will not come out. The low speed jet came out with a little resistance but otherwise undamaged.
This is the best instructional video I have ever seen on the web. The detail that you go into is essential for a full understanding of the job. Your video gave me the knowledge and confidence to clean the carb which turned out to be the source of my problem - very rough and unreliable idle. Question - are you a rigger for the University of Michigan?
I have a 2004 mercury 15hp 4 stroke and it will only run when the choke is on. Fuel is getting to the carb and the motor and carb looks very clean, however the brass plug has been drilled out. Before I pull the carb to clean do you have any ideals. Thanks for a great video. Ron
so this a great video and it helped me learn how to clean the carb out but it didnt help my problem. any idea what else would cause my motor to stall as soon as i push the choke in? i cant figure it out for the life of me. i have a 2003 9.9 honda 4 stroke. any help would be greatly appreciated.
Sounds like it's just not getting enough fuel, this can be caused by a dirty carb, but if you just cleaned it up, I'd recommend enriching the mixture a bit (turning the brass screw that is behind that brass plug counter clockwise). There's instructions on that in the last 1/3 of the video. Hope that helps. Let us know if you are still running into problems.
Devin: It sounds like your pilot jet is clogged. With the low quality fuel with ethanol we have today if it sits in the float bowl for very long it will evaporate and leave a gummy residue in the jets often clogging them. It is a common problem on carbureted motorcycles. Pull the float bowl and look at both the main and pilot jets. I bet you will find at least one of them clogged. When finished using the motor, disconnect the fuel hose and let it idle until it runs out of fuel in the bowl and the engined stops. Then it is empty and won't gum up the jets.
i have a 2003 Yamaha four stroke 15 hp outboard and i think you are right about the float and needle being stuck or closing . i feel that the float is too stiff and hard... i have a small leak of gas coming out from one of the four screws of the cover , what do you think is causing it? it has a new diaphragm, and new seals but when i prime it gas comes out from the screws..
If the O-ring (or in the case of this carb, the square ring) is not fully seated in the recessed edge along the outer edge of the bowl you can expect leaking. If you are having trouble getting the o-ring or seal to fit (like it seems too big), let it sit out overnight at room temp (being squeezed between the bowl and carb when assembled makes them expand, then you take off the bowl, bang, it no longer can be crammed in there). Any dirt or nicks, scratches, etc. that prevent perfect contact between the rubber ring and the bowl / bottom of the carb will let fuel get by. On something 12 years old it may be time to spend $15-25 and get a new square o-ring that is not cracked or hardened by time, if on a budget, use a very thin bead of black gasket maker from the auto parts store (follow directions on tube) and that can help seal it up. Don't use too much! As for the float, it should be a hard plastic that flops freely up and down. Check out our video of rebuilding a 20hp yamaha carb, a big thing to check is if gravity is enough to pull the float down (start with carb removed from motor and upside down, squirt carb cleaner into fuel line port, no cleaner should make it past the needle valve since the float is in closed position. Important part, with the carb right side up and just gravity pulling down on the float, do the same thing, cleaner should come through the fuel port past the needle valve, if not replace the needle valve and float (they can warp from heat, ethanol, etc.) What do you mean by new diaphragm? Fuel pump diaphragm?
Thank you very much for the detailed information. yes the fuel pump diaphragm i replaced it as well as the square o ring. however, i am having troubles when i throttle it it dies on me. it was running fine for a couple months and now i cant even go 5 feet with out it shutting off. thinking it was a fuel line problem i replaced but it still shuts off
fje137 Your next step is to remove the brass screw on the side that drains fuel from the bowl (hex screw with slotted head). Try running the motor, then when it dies, immediately remove the screw and the bowl should drain about an ounce of fuel out of it, if nothing comes out, the problem is somewhere in the fuel lines, or pump or basically between the carb and the tank. If fuel does come out (at least and ounce or more) then you have jets that are clogged and need a very thorough carb cleaning and possibly an idle mixture adjustment (could potentially be lean). Starting fluid in an aerosol can is a great diagnostic tool to spray at the intake of the motor as it is stumbling and about to die (if it picks up rpm and runs for a bit longer you are lean, if adding more fuel (the starting fluid) kills the motor, then you already have plenty of fuel and probably too much (running rich)).
i have taken off the screw and gas does come out. the carb was serviced and cleaned about a month ago. the only thing i have not done is the mixture adjustment in the (brass plug) since to my belief it hasn't been touched and it is still closed.
Great video. I have two questions. Should there be fuel in the priming pump assembly and hose to carb on the front of the motor? Mine has no fuel in the line. Secondly, can you show us how to convert a 8hp to 9.9 on the Mercury? Tx
Great video! Do you know if the 20hp is much different. Also I can't get the 10mm socket to the back bolt because the air intake is in the way. Any suggestions? thanks
My 2014 9.8hp Nissan outboard wants to die idleing. I cleaned the carb and it starts very easily (usually with one pull), but it keeps wanting to die on idle. Could excessive fuel supply be the culprit? Because for some reason, when I disconnect the fuel line, it idles very smoothly and stops sputtering and dying. Or should I mess with something else? Any suggestions would be greatly appreciated. And also, this is a great video. Very well done!
I have a 25 hp Merc Bigfoot 4-stroke, and this video was a help when I rebuilt it even though the carbs are entirely identical. One odd thing I found was a tiny ball bearing in the bottom of the plunger well. (At least that's where I think it fell from during cleaning.) Ball bearings in the carb are not mentioned anywhere in the shop manual. I just put it back into the well in the center opening at the bottom of the well. However, in quick engine run tests the engine hesitates and coughs under sudden acceleration. Has anyone else ever run across that little bearing? Is it supposed to be there or somewhere else?
need help my 9.9 4 stroke mercury when you pump the fuel bubble gas come out the overflow hose that is on top of the carb what will make it do that please help
+Jay Williamson Try adjusting the mixture, might be getting too much fuel from the accelerator pump, or could be that one of the high speed jets is plugged.
Hey thanks for the info earlier on. I bought a brand new rebuild kit which i had to take off and put in a new fuel / air mixture screw, (behind the brass plug), float and needle and its running amazing now with no problems while running .. however, now its flooding as if the bowl fills up too quickly. Can the air fuel mixture screw have something to do with that. Maybe to lean letting fuel go in to fast? i have put in the middle carb seal about 3 times (brand new) but the gas mostly drips out the outer bottom bowl screws. This now is flooding my engine which takes me about 5- 6 pulls to start it up again.. what is your professional advise? Thank you
This is one of the best mechanic videos I have ever seen. Every step is explained, all the parts and pieces are described, the functionality of the engine and components are relayed to the viewer. Thank YOU for taking the time to do this. I wish more mechanic videos were this great.
Oh man, you did more than just save me money, you gave me CONFIDENCE!. I just successfully fixed my 9.8 Evinrude (it's a Tohatsu engine, really) after watching your video. My motor died while out 2 days ago - and because it's spring all the shops are saying it's 3-4 weeks before they can even look at it. I changed out my gas first, tried Seafoam treatment but no luck. So, based on your video, I took the Evinrude carb off (it's pretty much identical). I followed your cleaning directions and re-assembled. Pumped the gas and she started 2nd pull ! And is now purring like a baby. I've never touched a carb in my life until today. THANK YOU.
I have had my boat/motor for about 5 years purchased lightly used. It started running rough and then not at all last season and has been parked since. I recently have wanted to use it but have no mechanical knowledge and searched for about 3 months for explanation’s to my issue with little answers leading to the carb, but no good step by step how to on fixing it. I was communicating with a local mechanic and set to drop it off in the next couple days, when I came across your video. Your well executed very easy to follow step by step vid gave me the confidence to do the job myself. Thank you so much for the knowledge and confidence you provided and God bless you!!
This was a very helpful video for me. The one thing that I’ll add is this (which I discovered while cleaning my carburetor) I started off by using starter fluid rather than carb cleaner to clean the parts. The first time I took it apart, I removed the gasket between the bowl and the rest of the carburetor and I had no problems fitting it back in. The second time I pulled it apart, I was using carb cleaner. Unlike the starter fluid, carb cleaner caused both my rubber gloves and the rubber gasket to expand. In order to fit the gasket back into place, I had to clean all of the carb cleaner off from the gasket and wait a few minutes for it to shrink back to normal size.
Dear Technician, thank you very much for this detailed and explanatory tutorial. With your step-by-step verbal and visual guidance I confidently disassembled, checked, cleaned and reassembled my Mariner 9.9's carburetor and gained an insight into its functioning mechanism. My motor is running smoothly again owing to you. Warm greetings from Mugla (Milas), Turkey.
I gotta pull mine back apart. Thought I cleaned it good, but I did not take the jets out and clean it. Put it back together and still did not run. This is the only video I watched that even took the jets out. Thank you👍
Thanks man, pulled them jets out and cleaned the them. Now it's running and idling great. Liked and subscribed.
I'm in the middle of this right now, frustrated as hell, took a break and found your video. This gotta be the most informative video I've ever watched. Bravo sir
Same. Just ordered a plethora of parts today
I also thought the float might be stuck in the open(down) position but that was not the case. I disassembled the carb and cleaned it as per the video - some clogging in the high and low speed jets but gave both a good cleaning.
I really think pumping the bulb rock hard forced too much gas to flow and stalled out the engine.
After reinstalling the cleaned carb and two pulls on the rope, she started right up on the third pull and runs like a charm, even at idle.
I would not have attempted this repair without this video. The first I could get in for a repair was one month away and goodness knows how much money.
I hope that this mechanic and his team will feel really encouraged do more videos.
They are providing an amazing service.
Sam
Thanks Rowintel for this outstanding video. It gave me, a novice mechanic, the confidence to dive in and clean the carb on my 8hp 4 Stroke Merc which was running rough or quitting at idle
and unusable for trolling. The carb was indeed dirty and I cleaned it per your instructions. In the process, I learned how carbs work. After putting it back together the engine started easily and purred like it should. The idle and mixture adjustments shown at the end of the video were invaluable. Fortunately, the brass plug for the mixture adjust screw had already been removed so I didn't have to deal with that drill out. Your background explanation and then step by step explanations exemplify what good how-to videos should be like. Well done and Thank You!
Glad it helped!
Mine just died coming into the marina! Clean it before it's too late! 😂
Could not have said it better !!! I am a good mechanic but a quick video when you are in new territory is a huge time saver. This was well done !!!
It’s been said, but wow, I think that is the best tutorial I’ve seen.
Thanks dude! A friend sunk my boat and the 9.9 merc was under water for a month before we got her up. I had no problem at all getting it to run again, but it would not run right. I knew it was the carb but had never taken one apart before. Using your excellent video here I took it all apart, cleaned, put back together in one hour. Motor started right up and runs great now. I was all set to spend almost $300 to have the local shop put a new one on. I thank you many times over for your excellent instructions. You did an excellent job.
Thank you SO much! Not only did your video teach me what I needed to know to fix my Mercury 9.9 kicker, which would not idle at all, but now, that particular problem will never cancel another boating event, like it did yesterday. All I needed was carb cleaner, two blade screwdrivers, rags, a 10 millimeter socket and an extension. I also used a guitar string which fit through the idle jet nicely and removed a stubborn piece of debris. I totally appreciate you sharing your knowledge. From now on that list of tools is on my sailboat.
Own a 15hp mercury and last weekend it started great but then stalled out.
Removed cowl and saw standing gas in the bottom of the housing. Cranked her over and gas poured out the bottom of the carb. This was after I had pumped up the primer bulb to rock hard as fellow at boat ramp suggested. Pulled the start cord again and motor ran briefly but rough.
I inspected the 2 plugs and both were badly flooded.
I let it sit for about an hour, pulled the cord and she again ran briefly but rough.
When I got the boat home I cruised You Tube and suffered through several abysmal videos on carb cleaning - no tripod, horrible sound, terrible lighting - one was even on a boat and was hand held - I almost got sea sick.
Your video is clean, well organized, great lighting and pretty good sound.
I think your use of the go pro for closeups was great.
I followed right along with your video in little chunks and eventually finished my carb overhaul.
I get to try it tomorrow morning.
Sam
Just used your video to clean my Merc kicker carb ...finished in half an hour because of your excellent explanations. Thanks!!
That shop is kept so neat, it looks well organized, and everything is in place.
Thanks, my motor had sat idle for a couple of years. I thought that allowing it to run out of gas by disconnecting the fuel line would prevent carb problems. It started after a lot of rope pulls but acted like it was starving for fuel. I replaced some components of the fuel supply system but didn’t help the prob. Checking with mechanic he thought it could be the carburetor and he could get to it in about 4 weeks and would cost $250 to $300. I watched your video and followed your instructions and it is running great. Starts first pull now and responds perfectly to the throttle. Great video. Thanks a lot.
The author's extra comments helps compensate for me not having anyone to help me. For example the brass/aluminum and stainless steel aluminum helped me. Also, confronting the reality of screw ups by telling the cost of both screws and carbs, helped us face the reality that 'screw' ups happen.
Great video and thank you... little 8hp is running like dream now. PAUL from Australia
Great video and tips! Gave me the nerve to fix my 9.8 4-cycle Tohatsu which started fine and would idle fine; however, it would shut off when throttled. Every 2-3 years I've had to take it to repair shop for similar problems - costing from $79-125 plus. Bought a can of carburetor cleaner for less than $4 and spent an hour or so carefully following you video. Removed, cleaned thoroughly, and reinstalled - started right up and ran perfectly! Thanks!
Thanks for the video. I have the TOHATSU MFS 8 that would kick over but not stay running. Felt it wasn't getting fuel and was hoping to find someone on TH-cam showing how to remove and service the carburetor. Easily removed and took apart the carburetor, thanks to your video. It was a mess and after a good cleaning runs awesome. Thanks again
Had trouble with poor idle performance. Followed this process and saved what was quoted as an $800 repair job. Engine ran just perfect without do the drilling out of the idle adjustment step. Thanks for the detail.
This was the best video out there. Watched it twice and went for it. So now my 9.9 is running like better than Dillinger after a bank robbery lol. Thanks.
Dude, your old video are gold. Thanks!
This was just the video I was looking for. Good job explaining the procedure - Your voice is easy to understand. I was hesitant to clean my 15hp Merc Prokicker. The motors are surprisingly similar. Thank you for a great lesson.
I ALMOST gave up on trying to learn how to do this. Thank you SO much. I watched so many useless videos where the author just assumed I knew how to do so many things. THANK YOU!
Thanks for the video! I followed your steps and cleaned my carb, getting my boat to run for the first time in 2 years.
Followed this tutorial and got my motor running! Thanks!
Thanks for this video, watched it while I tore my carb apart on the bench, very concise and went from non running pro kicker to an engine that purrs like a kitten and started first pull.
Thanks so much! You saved me $200 - and more importantly, you save me two out-of-order weeks during our precious short summer on the water
Great video! Got my 9.9 kicker fired up after watching this excellent presentation on how to take off the carb and clean out the jets! Thanks!
Great vid. I have the same 9.9 except 07' model. I had to clean the carb the other day and ever since it wants to die when I shift it into gear...I'm thinking it's the idel screw now that I've watched your vid. Great vid! Very in-depth and helpful.
Excellent Video and content. I like that you know the parts of your carburetor and you where very thorough with details. Fixed my 9.9 carb issue. Clogged low speed jet. Symptoms where would not run with closed choke. Gratitude.
Thank you for your information!!!!! I’m working on a 9.9 mercury and I’m pretty sure the jets are clogged I’m gonna fix it tmr with what I’ve learned
Great video, our 9.9 would not start this year, did whet you showed, fired right up, thanks for the great vid.
Thanks, I just learned a lot about my 9.9 Mercury.
I just pulled that overflow hose , thank god you showed me what it was and not knowing where the other end went too
Probably the best instructional video I have seen on youtube. Good going. can`t wait to open up my Mercury.
Thanks! Glad it helped!
Bought a 9.9 Merc brand new 2.5 years ago. Not 50 hours of run time after break in, it would either stall at mid throttle cruusing or stall coming off the throttle. Dealing with the dealership repair (under warranty) has been a nightmare (6 trips..long waits). Last trip was to another dealer...they actually got it running right. Said carb was dirty. That was about 3 running hours ago (two short trips) and I'm back to square one. I'm going to follow your instructions to see if i can get it running. BTW, this engine has never seen one drop of ethanol and i run the carb dry every time i get her home. Never buy a 9.9 Mercury.
Awesome video thanks for showing us , had to clean my carburetor after laying on wrong side while in a hurry, lesson learned.
Awesome breakdown and explanations Bro! Thanks for the education.
OUTSTANDING, I cleaned the carb reinstalled it and it ran fine. Late in the day I decided to run it again and it wouldn't idle. I took the carb off again and it was clogged again. fuel line and or filter had junk in it..
Very helpful. You made the job look easy. Motor is running great now thank you.
This video was so incredibly helpful, thank you
Great and detail video, quick question can I disconnect crank case hose to air cleaner, and run this hose to metal can with steel sponge (vapor)🤔
Yes great video, I been having trouble starting my 5 year old Tohatsu 9.8, changed plugs and fuel filter, once I got it stated I seen gas coming out top of carb, no hose. I'm thinking the float is stuck. I would never remove the carburetor but I will now after watching your video. Thanks
THIS IS......OUTSTANDING. Cleaned my carb today while watching this. Thank you.
@ 22:00. When putting that cover back on, I’ve discovered a small black gasket from someplace inside there. Does it (gasket) go on the bottom side of the spring where it rest in the fuel line connect, or does it sit at the top, between the plunger and the spring? Thanks.
Awesome video thanks from Canada
Thank you, this was a GREAT video and really helped explain all the impacts of the different adjustments.
Fabulous explanation. Unfortunately on reassembly I broke the choke into carb black connector piece which has been causing other issue. I realized I could start it in gear override so all good there. Critical is black piece must be turned to correct no choke position. The other day while running black piece somehow shifted on its own and caused breakdown. Not knowing the issue I rowed 1.5 mile back to boat.
I discovered this was the cause so decided to take out all the extra linkage parts and unfortunately took out linkage end connection piece with big spring behind it , oops!!! I am now unsuccessfully trying to reassemble that piece and cannot figure out the whole spring dynamic. I see one end goes into a little hole in carb. It appears other end goes against a part to keep it turned counter clockwise. Unfortunately cannot figure out how to do it or if I am correct. Wish I could show a picture. I have Mercury 8 ho 2015. Thanks.
Your are the man!! Thank you for an awesome video!!
I notice you are wearing the correct colors.
Great Video, it would be good if you changed the Title to 9.9 Mercury, Tohatsu and Evinrude Caburator Cleaning/rebuild.
I've owned both, a 2004 Tohatsu 9.9 and 2017 Evinrude. The engines are almost exactly the same, all made by Tohatsu. Great motors, but carbs need regular cleaning. I think a lot more people could benefit from your video with a little title adjustment. The Tohatsu and Evinrudes don't have the accelorator pump but I can see where it would of been as the carburator casting has everything for it.
Very nice video. Gonna try air/fuel-mixture screw on my Suzuki df15, that refuses to start. It starts eventually, but it takes way too long to be healthy. Carb has been cleaned twice now, but I haven't drilled out the mixture screw, now I'm Confident I can do it though very basic skill and Tools. Thanks man //Sweden
SwedishDylan Good Luck! Try cleaning the spark plug up real good too!
ROWINTEL.COM Allready installed new plugs in my first effort to get it running, nevertheless, it runs very well now. The mixture screw was way too lean, only about 3/4 out, so I set it to 2 and 3/4 (specs say 2 and 7/8)Thanks alot, really nice how you can help me from halfway round the World.
This is very thorough and informative
Excellent, really helpful, thank you.
Hi, thanks for the video . My engine, works fine, but twice stalled after going full power for 10 or 15 minutes. After a while it will start again and work perfectly. Also it does throw away some small amounts of fuel to the water after shutting it of. Sounds like flooding of the carburator, perhaps stuck float . Any chance of solving it without dissasembling thw whole thing ?
Great tutorial but a suggestion. You have to organize your shop and keep it organized. Shelves on the outside walls, a bench, a steel table and tool organizers. You’ll find you finish projects much faster.
Do you have any videos in adjusting and setting the throttle linkage??
thanks got a 02 merc 15 hp 2 stroke pull start. will not start but a tiny spray of starter fluid and she starts right up but dies. I figure it might had been the needle valve gonna crack it open this weekend
I have the exact same issue on the same outboard. Did you get it figured out?
Great video,mine is leaking fuel from what you did not take apart,the plunger that gives extra fuel when throttling up ,Iam getting a plunger diaphram for it. Am hoping take care of my leak
Thanks for the superb instruction - I followed along easily and saw improvement when I accelerate quickly. One thing that remains a struggle on my 4 stroke merc 9.9 is cold starting. Once started, it starts first pull, all day long. It is difficult to start without starting fluid and even more difficult to start without using the throttle only button and speeding up the throttle pretty high. I would really appreciate any suggestions you may have.
Great job! Go Blue!!
Did all but the main jet on my 9.9. That would not come out at all! Now to tune it to see if we can't fix the problem of stalling when going back to idle from a speed run.
Great Vid man i got a 15 hp merc its maybe a year or two old and im havng problem with high idle so shifting from nuetral to forward and vise versa is pretty violent. i realize i neeed to adjust the idle adjustmentment and mixture screw and mess with those next time on the water but im having trouble finding which screws are which, if you get this maybe you could post a pic with the idle screw circled and the air fuel mix screw circles too thanks.
Kyle Herrin I'll try to get a pic for you, but they are quite different. The idle adjustment screw (rpm adjustment) will directly contact the throttle plate and the screw head is parallel with the tiller (the screw head is aimed to the back of the motor), also the idle adjustment screw will have a spring wrapped around it. the idle adjustment screw will probably have to be backed out on yours to lower the RPM when shifting. You can see the screw with the spring at 29:29 in the video.
The air/fuel mixture adjustment screw is perpendicular to the tiller (faces the port side of the motor) and is nestled behind that brass plug you'll have to drill out (may have already been drilled out), also it is usually a flat head where the idle RPM screw is a Philip's. 29:29 in the video shows the screws pretty well.
On mercs there is another screw that is connected to the arm on the choke lever (this screw contacts the throttle plate when you pull the choke out). This screw has no impact on how the motor runs when the choke is pushed in, it just opens the throttle plate slightly when the choke is pulled out.
thanks, on top of the idle problems i just came to find out that the silver bar the connects the choke to the carb and the handle throttle to the carb is bent..more specifically the one that connects the throttle on the hand throttle to the actual carb. Does anyone have a part number or a name for this part? u can see the part inbetween you right thumb and index finger in the still of the youtube video
Thank you , thank you . Fixed the issue I was having
When I shift into reverse the engine goes into gear and high throttle all at once. N and F work totally fine. Direction to go in???
Devin: It sounds like your pilot jet is clogged. With the low quality fuel with ethanol we have today if it sits in the float bowl for very long it will evaporate and leave a gummy residue in the jets often clogging them. It is a common problem on carbureted motorcycles. Pull the float bowl and look at both the main and pilot jets. I bet you will find at least one of them clogged. When finished using the motor, disconnect the fuel hose and let it idle until it runs out of fuel in the bowl and the engined stops. Then it is empty and won't gum up the jets.
Excellent job just what I needed. Any chance you’d have the part number for the carb rebuild kit?
You are a genius. Thanks!
great video! On the low speed/idle jet is the hole that goes through the middle supposed to be the same size all the way through? I can blow through it and I can see a very small bit of light through it, but I can't send a small piece of wire all the way through. It goes part way in then hits up against something. Should I get a 32nd drill bit and drill through it?
Hi! My engine starts hard and runs rough when it starts. It shuts off multiple times and does react bad when giving it gas. However, once it runs a few minutes, the engine runs fine and picks up well when giving gas. Any idea what could be wrong? Thanks in advance!
Can you put a 13.5 carburetor on a Mercury 9.9? Ours is 20 years old and has corrosion.
Hi, i have a late model 9.8 tohatsu, it seems identical to the mercury. Can you do a video on how to change the timing belt. Not quite sure how to get the crankshaft pully off. Thanks
HI, I have the same engine as you but where I connect my throttle lever from the carb to the wheel, the wheel rotates and has a decent amount of play in it without me turning the throttle. Does the nut that holds the throttle pulley need to be tightened? It means my throttle will only engage when I'm almost at full power, in both reverse and forward, making small adjustments in power pretty much impossible. Thanks!
Excellent vid thank u
Man you need a work bench. It's killing to watch. Lol. Great job appreciated
Hi super great video . I did exactly what you do in this video but my problem ... The motor still on high revolution it doesn’t go to throttle speed. Even if I unscrew the gas screw it still too high ... What could be the problem ? Thanks in advance !
Any particular carburetor cleaner to use? Sea foam??
great video! can the mixture screw inside the brass plate unbalance itself . I believe my outboard is suffering from that which gives its a poor idle and also dies on me after 10 seconds of throttle
The mixture screw will not necessarily "unbalance" itself, however dirt, corrosion, varnish, etc. can restrict the orifice for the idle mixture (restrict fuel flow) over time. The motor uses so little fuel at idle that a sufficient amount of fuel may flow into the intake to start it, but not keep it running. Removing the brass plug, and unscrewing half turn at a time (wait 10-20 seconds of running time between turns to give things time to adjust) should fix that problem. As a long term solution, use ethanol free gas that is no more than six months old, and use the recommended amount of SeaFoam fuel additive to help stabilize the fuel and clean out any gunk that is in there. Good Luck!
One more question, i took off the lower unit to change the impeller but now i feel as if when i pull start it it slips. i did put grease but i made sure not to put it on the top of the shaft just around it , do you think i put it in wrong? i didn't know moving the prop would put it back in place, so i just pull started it slowly until it fit right in. it pees faster and cooler, and all the gears are operating to their function. however, would that be causing any problems in reference to it dying on me.
fje137 Really shouldn't cause any problems with it dying. If it is a salt water motor with extensive corrosion, then all sorts of weird things can happen (i've seen water being pumped into the intake, and high exhaust pressure block water flow, things that shouldn't happen if corrosion hadn't eaten away at the engine block and water lines). Greasing the splines on the drive shaft at the top is a good thing to do and should never cause slipping. Those splines are pretty heavy duty and as long as you have a 1/4" or more engaging and there is no obvious signs of worn down splines (i've never seen those particular splines slip) you should be fine. Check how much engagement you are getting by rotating the prop by hand with the lower unit in reverse (or forward) and slowly slide the lower unit back up onto the motor, note when the splines start to grab into the crank of the motor. most likely what you are feeling is the pull start mechanism slip (easy to replace and they do wear out). To confirm, bypass the neutral start lock-out mechanism, remove the kill switch so the motor won't start (maybe remove the spark plug wires too), and put the motor in gear, when the cord comes out the motor should turn and also turn the prop, if the flywheel on top of the motor is turning but the prop is not, then you do have some weird issue going on with the splines slipping on the driveshaft (this is pretty unlikely though)
Rowtel, I was wondering if you had any thoughts about gas octane. In the Midwest we have 10% ethanol. Someone recommended using 91 or 92. I’m wondering what your thoughts are. Thanks!
I need help. What's the little black thing on the carb that is sponge like? I need a new one but can't find one
Great job with video!!! Very helpful.
I own a 15hp, 4 stroke Mercury outboard, 1999. It will not run at idle. I can get it to idle briefly by giving it full choke.
I thought this indicated not getting gas at idle.
I followed along with your video and got to where you remove and cleaned both the high speed and the low speed jets. I got the brass high speed jet out, cleaned and replaced but I could not get the low speed jet out - I could get it unscrewed but was unable to get the actual brass jet removed for cleaned. I tried tapping with the carb upside down but the jet would not fall out.
I gave it a good shot of carb cleaner and will let it sit overnight and try again in the morning.
Any thoughts why the jet will not come all the way out?
Sam
Any advice on removing the main jet that just "falls out?" Mine is stuck good and will not come out. The low speed jet came out with a little resistance but otherwise undamaged.
This is the best instructional video I have ever seen on the web. The detail that you go into is essential for a full understanding of the job.
Your video gave me the knowledge and confidence to clean the carb which turned out to be the source of my problem - very rough and unreliable idle.
Question - are you a rigger for the University of Michigan?
I have a 2004 mercury 15hp 4 stroke and it will only run when the choke is on. Fuel is getting to the carb and the motor and carb looks very clean, however the brass plug has been drilled out. Before I pull the carb to clean do you have any ideals. Thanks for a great video.
Ron
so this a great video and it helped me learn how to clean the carb out but it didnt help my problem. any idea what else would cause my motor to stall as soon as i push the choke in? i cant figure it out for the life of me. i have a 2003 9.9 honda 4 stroke. any help would be greatly appreciated.
Sounds like it's just not getting enough fuel, this can be caused by a dirty carb, but if you just cleaned it up, I'd recommend enriching the mixture a bit (turning the brass screw that is behind that brass plug counter clockwise). There's instructions on that in the last 1/3 of the video. Hope that helps. Let us know if you are still running into problems.
devin shafar
paladin2043
16 hours ago
Devin: It sounds like your pilot jet is clogged. With the low quality fuel with ethanol we have today if it sits in the float bowl for very long it will evaporate and leave a gummy residue in the jets often clogging them. It is a common problem on carbureted motorcycles. Pull the float bowl and look at both the main and pilot jets. I bet you will find at least one of them clogged. When finished using the motor, disconnect the fuel hose and let it idle until it runs out of fuel in the bowl and the engined stops. Then it is empty and won't gum up the jets.
Great job man!
I have this same exact carburetor but I can’t find a rebuild kit. I’m about to have to buy a new carb all together
i have a 2003 Yamaha four stroke 15 hp outboard and i think you are right about the float and needle being stuck or closing . i feel that the float is too stiff and hard... i have a small leak of gas coming out from one of the four screws of the cover , what do you think is causing it? it has a new diaphragm, and new seals but when i prime it gas comes out from the screws..
If the O-ring (or in the case of this carb, the square ring) is not fully seated in the recessed edge along the outer edge of the bowl you can expect leaking. If you are having trouble getting the o-ring or seal to fit (like it seems too big), let it sit out overnight at room temp (being squeezed between the bowl and carb when assembled makes them expand, then you take off the bowl, bang, it no longer can be crammed in there). Any dirt or nicks, scratches, etc. that prevent perfect contact between the rubber ring and the bowl / bottom of the carb will let fuel get by. On something 12 years old it may be time to spend $15-25 and get a new square o-ring that is not cracked or hardened by time, if on a budget, use a very thin bead of black gasket maker from the auto parts store (follow directions on tube) and that can help seal it up. Don't use too much!
As for the float, it should be a hard plastic that flops freely up and down. Check out our video of rebuilding a 20hp yamaha carb, a big thing to check is if gravity is enough to pull the float down (start with carb removed from motor and upside down, squirt carb cleaner into fuel line port, no cleaner should make it past the needle valve since the float is in closed position. Important part, with the carb right side up and just gravity pulling down on the float, do the same thing, cleaner should come through the fuel port past the needle valve, if not replace the needle valve and float (they can warp from heat, ethanol, etc.)
What do you mean by new diaphragm? Fuel pump diaphragm?
Thank you very much for the detailed information. yes the fuel pump diaphragm i replaced it as well as the square o ring. however, i am having troubles when i throttle it it dies on me. it was running fine for a couple months and now i cant even go 5 feet with out it shutting off. thinking it was a fuel line problem i replaced but it still shuts off
fje137 Your next step is to remove the brass screw on the side that drains fuel from the bowl (hex screw with slotted head). Try running the motor, then when it dies, immediately remove the screw and the bowl should drain about an ounce of fuel out of it, if nothing comes out, the problem is somewhere in the fuel lines, or pump or basically between the carb and the tank. If fuel does come out (at least and ounce or more) then you have jets that are clogged and need a very thorough carb cleaning and possibly an idle mixture adjustment (could potentially be lean). Starting fluid in an aerosol can is a great diagnostic tool to spray at the intake of the motor as it is stumbling and about to die (if it picks up rpm and runs for a bit longer you are lean, if adding more fuel (the starting fluid) kills the motor, then you already have plenty of fuel and probably too much (running rich)).
I very much appreciate having the time to reply to my inquiries. thank you so much, i will definitely try it out.
i have taken off the screw and gas does come out. the carb was serviced and cleaned about a month ago. the only thing i have not done is the mixture adjustment in the (brass plug) since to my belief it hasn't been touched and it is still closed.
Great video. I have two questions. Should there be fuel in the priming pump assembly and hose to carb on the front of the motor? Mine has no fuel in the line. Secondly, can you show us how to convert a 8hp to 9.9 on the Mercury? Tx
Great video! Do you know if the 20hp is much different. Also I can't get the 10mm socket to the back bolt because the air intake is in the way. Any suggestions? thanks
solid! thanks for sharing this
My 2014 9.8hp Nissan outboard wants to die idleing. I cleaned the carb and it starts very easily (usually with one pull), but it keeps wanting to die on idle. Could excessive fuel supply be the culprit? Because for some reason, when I disconnect the fuel line, it idles very smoothly and stops sputtering and dying. Or should I mess with something else? Any suggestions would be greatly appreciated. And also, this is a great video. Very well done!
sounds like the mixture should be adjusted, look towards the end of the video for how to adjust flat head screw.
I have a 25 hp Merc Bigfoot 4-stroke, and this video was a help when I rebuilt it even though the carbs are entirely identical. One odd thing I found was a tiny ball bearing in the bottom of the plunger well. (At least that's where I think it fell from during cleaning.) Ball bearings in the carb are not mentioned anywhere in the shop manual. I just put it back into the well in the center opening at the bottom of the well. However, in quick engine run tests the engine hesitates and coughs under sudden acceleration. Has anyone else ever run across that little bearing? Is it supposed to be there or somewhere else?
need help my 9.9 4 stroke mercury when you pump the fuel bubble gas come out the overflow hose that is on top of the carb what will make it do that please help
thanks so much for the video.. helped solve my problem!
Great video. I have a 2006 9.9 and it idles fine but when I go to throttle up it stalls. What do you think the problem is?
+Jay Williamson Try adjusting the mixture, might be getting too much fuel from the accelerator pump, or could be that one of the high speed jets is plugged.
Hey thanks for the info earlier on. I bought a brand new rebuild kit which i had to take off and put in a new fuel / air mixture screw, (behind the brass plug), float and needle and its running amazing now with no problems while running .. however, now its flooding as if the bowl fills up too quickly. Can the air fuel mixture screw have something to do with that. Maybe to lean letting fuel go in to fast?
i have put in the middle carb seal about 3 times (brand new) but the gas mostly drips out the outer bottom bowl screws. This now is flooding my engine which takes me about 5- 6 pulls to start it up again.. what is your professional advise? Thank you
Is this engine pretty much the same as a 2007 tohatsu 8hp?