This is the best or possibly the only video how to cure a sneezing Yamaha 20-25HP outboard engine! My 25HP Yamaha from -93 did exactly the same sneezing thing, and it's now running like it was new, thanks to your excellent instructions! Thank you for posting this! I'm truely greatful for your efforts! Also your video about tuning the fuel screws at idle helped me get my motor running like a charm! From not being able to go hardly anywhere with the boat, I'm now able to actually make longer boat trips with the family! :)
That's what my Yamaha 40 Hp was doing when I bought it used. Did the carb clean, fuel tank, lines, plugs and still was the same. I saw this video and noticed my butterfly valves were uneven, checked my linkage that controls them and notice that they were upside down. So the entire time all I had to do was flip the linkage. But your video made me check those valves, and sure enough it was so simple to fix. Thank you so much from Victoria B.C. Canada
The joys of being a mechanic, is that we learn something new every day, and we need to be open minded, as I have learnt how to fix issues from the strangest people.sometimes the old bush mechanic can teach us a thing or two Good work well done, gold coast Australia
Bought a 1981 Yamaha 55B and in short - I tried to make it run without success - watched many youtube videos - finally found this one - and a day later it is running. Thank you for to the point instructions. Waiting for 2021 boating season here in Finalnd.
Thanks for the acknowledgement. I appreciate it. I tell my customers to watch your vids if they want to learn a little about outboards. Keep up the good work.
Ha! That cracks me up. Ive been to Philly. Twice. I believe I've seen the Liberty Bell, went up the Rocky steps, and had a cheesesteak. My quota is filled.
i loved this little series on the single outboard. Would love it if u made more videos of knowing how to diagnose issues then fixing them on that outboard, but also keep up the more specific videos separately. Loving all your videos
This video is very helpful to me right now!big thanks.I just cleaned all 3 carbs and each carb has 2 floats it’s more like 6 carbs!now it’s time to sink them all!Ill keep watching this video a few more times 👌👍
I found out the bigger problem that I had!Im wounding if you agree?all the rain we had for two week here keep the pump and flit switch running a lot!right after that my motor would turn over for a while then die and never start.my two deep cycle battery with a 20watt solar set up did not keep up.too small,the 225 hp on my 19.5 boat did not have enough spark to tune over this motor needs very high amps to not just make the starter run but all the other electric ignition components!nothing worked except two new deep cycle battery.I tried to make a jumper start switch like in one of your videos and it turned it into a electric welder!lol this big old motor needs amps!I need bigger solar panels 👍or less rain ,one long week of fun this has been!all for a 50 mph fishing boat
Hey danger, can you make a video of adjustment in the timing on 25/30 yam 3 cylinder? There is not any video of these motors. Thank you very much man, you do a awesome job education people with your videos
Great find. This is a prime example of why you consult a professional for repair. I would have went toward the fuel pump. It's your experience and knowledge that shines in these type of repairs that in the end costs less money because you know where to look and diagnose. Well done and great video!
I have a Suzuki DT 55 that shows exactly the same issues. I also know that the center carb throttle plate is fractionally ahead of the other two. Stupidly I hadn’t considered this to be significant enough but I’m ready to get at it. Thanks, I’m feeling more confident that I may finally solve the sneezes.
Update; I just followed your tutorial on my DT 55 and transformed my slow running issues. Thanks, you truly are a very valuable. Source of information !!!!!
This may come into use. I’m looking at a 1989 Johnson 25hp, the motor has that 2 stroke sneeze when the guy fired it up after it’s sat for a year. Compression is at 140 in each cylinder, new spark plugs. But on your previous vids of this Yamaha some things I would have never know to look for, so thank you!! I’d like to get a Yamaha instead, but here in the states they are a fortune used. Johnson and mercury is not to bad priced used. The average price for either of them is about $800-$1500 anywhere between 20-30 years old. The Yamahas used are between 20-30 years and they want $2500 or more. Supposedly there’s more parts for older Johnson out there than older mercs. We shall see.
Great video. I’ve been sitting with exactly this issue on a similar model 25hp Yamaha. Exact same setup. Going to go through this and hopefully get rid of the sneeze
Awesome Stu, glad this one doesn't have a cold anymore. interesting carb setup on this one. my merc has less moving parts to deal with but the sync is the same. glad it was an easy fix and not a major one.
My Johnson 110 was coughing and getting hard to start so I took the carbs off and cleaned them. Starts better but has a slight cough but not as bad so I’m going to look at the butterflies like you did and figure out the rest seeing the carbs are different. Nice video good details.
So impressive you foundthe problem, im actually having the same problem but with a 15 hp mercury 2 stroke. just one carburetor though, which i rebuild, but still the same problem. I am working on outboards myself for over 10years now but never came across such a problem. It's true that 80% is a dirty carburetor, but this is just insane. I got a vacuum leak via the butterfly axle and mechaniced the shit out of it, blocked one end off and an 0-ring on the other end so it leaks no more and handles exactly the same... this is just insane.
DAMN YOU !!!!! Your videos are so good, I spent another 2 hrs on this damn computer!! I don't know if I should hate or love you. I'm confused but I know one thing for sure, I wish I had a shop instructor that was half as good as you. Please keep up the videos, we need people like you.
Now my 2 friends are watching also. I actually learned more from your videos than anything else. You're truly an awesome teacher and your passionate about what you do. I'm rebuilding a 98 sea ray searayder jet boat. I hope you do something on jets sometime cuz you got 3 big fans right here.
Yamaha has this problem, and it was also in the RD-400 engine, sync the carbs or it won't loft the front wheel. My family saw me riding that bike several times, my old man remarked about only one wheel being used at any one time, I think that is why two strokes were discontinued, it wasn't about emissions. I had fun with that bike, I also really liked the Kawi H-2 triple two stroke, that thing was a screamer. That H-2 went 11,500 rpm in third at well over 90 inside the school parking lot. The RD handled, the H-2 went well in straight lines. H-2 didn't turn worth a damn.
I’m going to go try this on my 78 115hp Evinrude tonight. She bogs spits and dies at low idle. Cleaned the carbs and found rubber under the float needle seat AND low speed jet was plugged with the same type of rubber. Was leaking fuel all over and wouldn’t start. After the carb clean, new fuel pump, new fuel lines the motor now sputters and dies. Hoping it’s just a loose connection like you show here. I think I remember looking into the butterfly chamber and saying to myself “ hmm it’s not closed all the way AND it won’t open all the way”. Didn’t do anything about it cause I didn’t see this video yet!! Thank you. Hope this is what fixes “The Little Bogger”.
It seems like the smaller the motor, the more important it is to have the carbs synchronized. I know its bad for all motors but seems there isn't as much wiggle room on the smaller motors. Great job as always Stu!!!
I think you're on the money there, small motors do seem to be more sensitive. About the only motor I could never get running no matter how much I tried was a chainsaw.
Dangar Marine Haha Stu. Its crazy you just said that. I swear to god right now Im in my Dangar Marine shirt cutting a big broken pecan tree with a Dolmar chainsaw that i got running but I can only get it running at a crazy fast idle that scares the crap outta me. Pouring sweat in this hot louisiana weather. Too cool you said that bud!
I knew it lol. Actually I was expecting the bore of one or both of the carb butterfly shaft(s) to be worn. It still great showing how diagnostic leads a person around like that. I once as a teen rebuilt a car engine because I thought I had a head warped.. Turned out a line to the turbo after all of that. No worries though because it really was due at 230k miles I guess.
Manometers are used with four strokes where you have an intake manifold vacuum to measure. You can use a flow meter on the front of the carburettor though.
In this series I learned so so much. Its 1 a.m. and its worth of being so tired. But I couldnt stop watching all the episodes around that little 2 stroke.
Hi Stu, my oldest son has a small older merc 2 cylinder 110. I think it's a 9. something hp. he brought it over for me to help him change the impeller but has other issues. I will gopro this week for fun.
i have a yamaha 40hp 3 cylinder from 1986 with this "sneezing" problem on the third cylinder, it revs up fine but at lower rpm and idle it sneezes. carbs are clean and reed valves looks good
Bloody excellent series of videos - if only I had access to material like this back in the 1980's when I had my boats. What did we do before the interwebnet, eh??
I have learned so much by watching your channel! thank you Sir. I have a 50 HP Yamaha 2stoke that keeps getting clogged jets. almost immediately after cleaning. I have replaced all fuel lines, filters, fuel pump, and ran it on a separate fuel tank. My next step is to replace the spaghetti gaskets or orings inside the carbs. they have some type of gel stuck to them. it was like this when I bought the boat. have you ever seen these gaskets cause this type of problem?
Once gaskets and o-rings start to disintegrate they can certainly cause these types of problems. It's good that you have changed the fuel lines as these are a big cause of trouble once they get old.
Wish you was in tennessee in usa..we need someone like you here..you care about what you are doing..i see that very easy..did you go to lots of training..or did you educate yourself.. God bless
mate why didnt you just sync the carbys in the first place ,,,,JUST KIDDN,, loved the video,,always so informative,,,one of the best videos,,,please keep up the fantastic work...I did have a problem with a slugesh motor,,it was a leaky fuel pump diafram...hopefully we will meet one day as i fish near were you live...take care friend.....cheers Brett
Thank you Stu, I was eagerly awaiting this video. More good work. Greatly appreciated. I will be down your way in a month or so, where is your workshop, is it at Brooklyn, I am thinking of paying my debt for all the info. Cheers, Bruce.
Stu, you had better email me your address and a phone No. alanvale at gmail dot com and I will send you my details also. Interestingly my mate lives at Berowra, just next door to Mt Kuring-gai Cheers mate.
Awesome Stu. I had no idea that these engines were that sensitive to carburetors not synchronized perfectly. I definitely learned something from watching this. Is it possible to remove the carbs for cleaning and not disturb the sync settings?
Just did this to my old Yamaha. Stripped and cleaned the carbs, they always needed damp start to get it going. Put them back together exactly as they were, started it with no damp start (yay) but had this same issue. Followed this video, brilliant, fixed it. Cheers. One question, is it wrong that it runs better with one of the mixture screws screwed all the way in? The other one is 4 half terns out at the moment. Thanks again, brilliant instructions. Keep em coming.
Hey Malcom, it is a bit odd that one is screwed all the way in, it sounds like that is compensating for a problem but if it runs well I wouldn't worry too much.
Dangar Marine. Hi Stu, thanks a lot for your reply. Next time I'm out I'm going to have another play around with the mixture screws just to be sure this is the best setting. Great videos. Cheers
Well, that was easier than I thought it would be. I figured you would break out a mercury carburetor sync tool. But then, I didn't see any vacuum tube ports on the sides of those little Yam's carbs to attach the tubing to.
thanks so much for the lesson. question: At 8:20 you say motor is hard to start, so you add more air by opening the butterflys. Isn't a closed butterfly the same as a full choke, which makes it richer and easier to start? And what is the choke mechanism? Obviously it worked, but why? Motor was warm from many video takes?
this same this is happening to my Mercury 40hp 2 cyl. 1 carb.. cleaned carbs and fuel lines, same spark plug issues, same "fix" when one wire pulled.. but I only have one carb..
Do these motors have a vacuum port, to sync that way - like you did in a previous video? I'm assuming no, but wanted to check. In the process of purchasing a service manual.
A quick question if you have the time, with my V6 2005 150HP mercury 2 stroke, I've noticed it has 3 carbs fitted but i'm assuming each body contains 2 carbs (so 6 all up) that I'd need to sync using this method ? I find your video's to be very informative and your method of presentation makes it easy to understand, and gives me the confidence to tackle this job. Also how would I know if my outboard was running rich ? is it simply by ensuring that the mixture screws are set to factory settings and thats it ?
Hey Dangar Marine .. Your videos are really good ive subbed and subscribed..I Just came home from doing a link and sync on a F150 at YAMAHA MARINE UNIVERSITY in Atlanta USA and my question is that the instructor told us that it would be best to do this in the water or a very least in a bucket.. I was just curious is it would make that much difference with a load on it.. We had to adjust the TPS to Meet the ISC request at around 42 degrees. THanks for you videos again. MiKe.
Hi Mike. Trust me, you probably know a lot more about these big Yamaha's than I do! This motor doesn't have any idle speed control other than a simple set of mixture and speed screw. These definitely need to be adjusted warm with the motor in the water but I don't imagine it is so important when adjusting the relationship between the butterfly linkages. Would be interested to hear what your teacher thinks though.
I have a 40 2T yamaha. Cleaned carbs. Adjusted idles - starts fine and runs smoothly but as soon as open throttle or push down linkage she cuts out. So my guess is fuel delivery issue so ordered new pump and filter - after this what else could it be ...?
Hey Stu, another great and well made video!!! I am trying to understand how the "out of sync" carbs could have this effect on the motor!?! Obviously it did but can't comprehend fully. Haven't seen the Green Machine in a while, all good I hope. Cheers
Good day sir. I'm a fairly new subscriber to your channel. First of all I have to say you your videos have helped me tramendously. I have what I think is a 1988 90 hp 6cyl Mercury outboard with 3 carbs. I have rebuilt the carbs new coils, wires, plugs, compression on cylinders is 150 lbs almost dead on in each cylinder. Number 5 cyl is acting exactly the same as the cylinder in this video. The only things I haven't done that you have in this series. Is the head gasket, and the Reed valves. Before I do that. I wanna time the engine, and sink the carbs. My question is. Does the same procedure apply to my engine as this one. Would the carbs be adjusted the same way, and have never timed an outboard engine before. Any help you could give me, would be extremely helpful. Oh by the way great videos on the electrical set up on the green machine. Got my 76 Marquis wired up perfect thanks to you.
Hi Brian. The principle of the carb sync is the same, I just can't picture what the adjustment options are like on the old Merc. From memory timing adjustment is quite simple on those older Mercs using a timing light.
Getting game again announcing what next weeks video will be about :-) at about 09:50 is that that an edit double up ? And I wish the Johnson 50 twin 'link and Sync' was as simple as your engines. The OMC process is very fiddly, and the book states the engine is sensitive to the cylinders being out of sync.
Ron Powell I have an evinrude 48 SPL. It's essentially the same as your Johnson 50. I've seen the sync and link procedure in the manual, and I agree it doesn't look easy! Hoping I never have to do it.
Hmmm, I'd be interested to look through the procedure. Somebody just gave me a Johnson service manual recently. I think that "double up" was just me being repetitive rather than an edit.
Fireship1 - they ARE the same engines other than the cover sticker- well too close to be of any consequence. The difference between the 50 and the 48 is only where the HP rating is measured- 50 at the flywheel, 48 at the prop.
I have a Lowe deck boat with a Johnson 150 motor, salt water edition. I live at a small lake in Texas, fresh water, and the lake was to low to put the boat in for about 5 years. Last year I put it in the water and on idle it runs ok, but when I get into the high rpms or pulling a tuber it will sound the hot motor buzzer and starts cutting out big time. I can turn it off and the turn it back on immediately and I'm going full bore for a while then it does it again. Some times it happens pretty quickly and then again it may be quite a while. I have blasted the carbs with the cleaner at the brass front fitting and they seem clear. I have also replaced the water intake impeller. It has a separate tank for the oil and I thought that may have a problem since its set up so long. Do you have any ideas? Thanks and I really enjoy your videos.
Hi Terry, I'm not overly familiar with those Johnsons, but I presume there will be some way to tell if it is an overheat or an oil alarm. If it is an overheat it may be the thermostat stuck closed so even if the pump is good, the water won't be going through the head.
Dangar, are you still posting material on the web? Really appreciate how you explain things. I have an Evinrude VRO 140, and I think I have a carburetor throttle linkage issue. Wish me luck! thanks man!
Your vids are so addicting I binged-watched this yamaha story... and I don't even have a yamaha! But it did bring up a question for my 1995 200hp Evinrude. In order for it to run smoothly, all six carb screws need to be backed off 6 1/2 turns. Seems excessive but it's the only way to get her to run nicely. Think the amount of screw turns are affected by something else so I can save some fuel? Thanks for the knowledge.
I want to sync and tune 3 carbs on a 1966 outboard, and hoped maybe you could clear up some questions I had after watching the video. Appreciate the way you explain things! You coarsely set the fuel mixture, and then your steps to sync basically boil down to only one concept: make sure the plates are at the same position at the same time. Sure, you also adjusted the amount of open-ness at idle for good idle, adjusted the throttle cam, then readjusted to make sure you can get full throttle, but basically sync is achieved "only" by setting the plates the same. Is that really the gist of it on a 2 stroke? i.e.e you didn't show more about the fuel mixture screws, and there was no statment that vacuum is the only way to truly achieve balance. Are those steps required as well? There's nobody I can find to work on my 3 cyl 75hp McCulloch, so I need to understand it well and do it myself! Thanks in advance for any add'l clarification you'd be willing to offer!
Dennis, yep, pretty much have the procedure for a two stroke. This vid is on a four stroke, but all the mixture and idle speed stuff is the same th-cam.com/video/bsHCMJnRY9A/w-d-xo.html
You mentioned balance/synchro is different for 2-stroke vs. 4-stroke engines. Why? Isn’t measurable vacuum the same variable for setting air flow and fuel mixture for both types engines, regardless of how the vacuum is regulated (via reeds or valves)? If not, What’s the difference in procedure for synchronizing carbs on 2-strokes?
Can anyone tell me roughly the year and/or model of this 20hp yam. I have one looks same but cant read the id plate. Im looking for carby kits to suit them carbies, any response appreciated.
Hi how are u,,i have 25hp 2 stroke yamaha enduro with one carburettor ,it was running ok but when i cleaned the carb this problem start to happen (backfire and no power at all) hope u can help me
I synchronized my carbs I have a 48 hp envinrude 2 stroke, when start it up does really good but next day when trying to start it up it off again wonder why.
Start with 2 turns out and tune from there. There isn't an exact amount, if there was they wouldn't need to be adjustable. This vid might help, just ignore the vacuum gauge stuff as it is a two stroke th-cam.com/video/bsHCMJnRY9A/w-d-xo.html
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To this day, still the best educational outboard videos out there! Fixed my "Sneezy" motor problem as well!
Thanks Thomas, glad to hear you got your engine fixed up! :)
This is the best or possibly the only video how to cure a sneezing Yamaha 20-25HP outboard engine!
My 25HP Yamaha from -93 did exactly the same sneezing thing, and it's now running like it was new, thanks to your excellent instructions!
Thank you for posting this! I'm truely greatful for your efforts! Also your video about tuning the fuel screws at idle helped me get my motor running like a charm!
From not being able to go hardly anywhere with the boat, I'm now able to actually make longer boat trips with the family! :)
Thanks mate. Great to hear you are now out and about enjoying your boat. :)
That's what my Yamaha 40 Hp was doing when I bought it used. Did the carb clean, fuel tank, lines, plugs and still was the same. I saw this video and noticed my butterfly valves were uneven, checked my linkage that controls them and notice that they were upside down. So the entire time all I had to do was flip the linkage. But your video made me check those valves, and sure enough it was so simple to fix. Thank you so much from Victoria B.C. Canada
The joys of being a mechanic, is that we learn something new every day, and we need to be open minded, as I have learnt how to fix issues from the strangest people.sometimes the old bush mechanic can teach us a thing or two
Good work well done, gold coast Australia
For sure, there is always some new trick to learn that comes from the strangest places!
Finally found the solution to my sneezy 25hp yamaha. I would definitely put Yamaha in the title, as there arent any other videos for
Glad it helped!
Bought a 1981 Yamaha 55B and in short - I tried to make it run without success - watched many youtube videos - finally found this one - and a day later it is running. Thank you for to the point instructions. Waiting for 2021 boating season here in Finalnd.
Great to hear!
Thanks for the acknowledgement. I appreciate it. I tell my customers to watch your vids if they want to learn a little about outboards. Keep up the good work.
Ha! That cracks me up. Ive been to Philly. Twice. I believe I've seen the Liberty Bell, went up the Rocky steps, and had a cheesesteak. My quota is filled.
...an excellent teacher. Thanks for all the time you put in dangar stu! Subscriber forever!
had this issue on single carb 25.
literally the butterfly screw fixed it.
cheers Stu. great video as always.
i loved this little series on the single outboard. Would love it if u made more videos of knowing how to diagnose issues then fixing them on that outboard, but also keep up the more specific videos separately. Loving all your videos
Thanks mate. Going to be doing a bit of diagnosis on a Merc 110 9.8 that won't start today. We'll see where that leads us.
This video is very helpful to me right now!big thanks.I just cleaned all 3 carbs and each carb has 2 floats it’s more like 6 carbs!now it’s time to sink them all!Ill keep watching this video a few more times 👌👍
Glad the vid helped Bruce. :)
I found out the bigger problem that I had!Im wounding if you agree?all the rain we had for two week here keep the pump and flit switch running a lot!right after that my motor would turn over for a while then die and never start.my two deep cycle battery with a 20watt solar set up did not keep up.too small,the 225 hp on my 19.5 boat did not have enough spark to tune over this motor needs very high amps to not just make the starter run but all the other electric ignition components!nothing worked except two new deep cycle battery.I tried to make a jumper start switch like in one of your videos and it turned it into a electric welder!lol this big old motor needs amps!I need bigger solar panels 👍or less rain ,one long week of fun this has been!all for a 50 mph fishing boat
Hey danger, can you make a video of adjustment in the timing on 25/30 yam 3 cylinder? There is not any video of these motors. Thank you very much man, you do a awesome job education people with your videos
Great find. This is a prime example of why you consult a professional for repair. I would have went toward the fuel pump. It's your experience and knowledge that shines in these type of repairs that in the end costs less money because you know where to look and diagnose. Well done and great video!
You are the best at explaining things..i always learn a lot from watching your videos.
God bless bro.
So nice of you. :)
I have a Suzuki DT 55 that shows exactly the same issues. I also know that the center carb throttle plate is fractionally ahead of the other two. Stupidly I hadn’t considered this to be significant enough but I’m ready to get at it. Thanks, I’m feeling more confident that I may finally solve the sneezes.
I too didn't realise what a bit difference it would make.
Update; I just followed your tutorial on my DT 55 and transformed my slow running issues. Thanks, you truly are a very valuable. Source of information !!!!!
This may come into use. I’m looking at a 1989 Johnson 25hp, the motor has that 2 stroke sneeze when the guy fired it up after it’s sat for a year. Compression is at 140 in each cylinder, new spark plugs. But on your previous vids of this Yamaha some things I would have never know to look for, so thank you!! I’d like to get a Yamaha instead, but here in the states they are a fortune used. Johnson and mercury is not to bad priced used. The average price for either of them is about $800-$1500 anywhere between 20-30 years old. The Yamahas used are between 20-30 years and they want $2500 or more. Supposedly there’s more parts for older Johnson out there than older mercs. We shall see.
Been following your channel for sometime, really enjoy how you explain things.
Awesome, thank you!
Great video. I’ve been sitting with exactly this issue on a similar model 25hp Yamaha. Exact same setup. Going to go through this and hopefully get rid of the sneeze
Awesome Stu, glad this one doesn't have a cold anymore. interesting carb setup on this one. my merc has less moving parts to deal with but the sync is the same. glad it was an easy fix and not a major one.
I was pleased too when it started running nicely. Time for it to go back in the water!
My Johnson 110 was coughing and getting hard to start so I took the carbs off and cleaned them. Starts better but has a slight cough but not as bad so I’m going to look at the butterflies like you did and figure out the rest seeing the carbs are different. Nice video good details.
As always, so informative. You just simply are the best
I appreciate that!
Awesome video!! Thanks for sharing, love this series. I have been using them to service an old yammy 20hp and the motor is now running great!
Never in a lifetime would thought that! nice video , i'm very happy to see it fix
I must admit, I was surprised to see how badly it ran for such a minor problem.
Presented in an easy to understand manner, as usual. Thank you.
Thanks mate. :)
So impressive you foundthe problem, im actually having the same problem but with a 15 hp mercury 2 stroke. just one carburetor though, which i rebuild, but still the same problem. I am working on outboards myself for over 10years now but never came across such a problem. It's true that 80% is a dirty carburetor, but this is just insane. I got a vacuum leak via the butterfly axle and mechaniced the shit out of it, blocked one end off and an 0-ring on the other end so it leaks no more and handles exactly the same... this is just insane.
DAMN YOU !!!!! Your videos are so good, I spent another 2 hrs on this damn computer!! I don't know if I should hate or love you. I'm confused but I know one thing for sure, I wish I had a shop instructor that was half as good as you. Please keep up the videos, we need people like you.
Thanks James!
Now my 2 friends are watching also. I actually learned more from your videos than anything else. You're truly an awesome teacher and your passionate about what you do. I'm rebuilding a 98 sea ray searayder jet boat. I hope you do something on jets sometime cuz you got 3 big fans right here.
Yamaha has this problem, and it was also in the RD-400 engine, sync the carbs or it won't loft the front wheel.
My family saw me riding that bike several times, my old man remarked about only one wheel being used at any one time, I think that is why two strokes were discontinued, it wasn't about emissions.
I had fun with that bike, I also really liked the Kawi H-2 triple two stroke, that thing was a screamer.
That H-2 went 11,500 rpm in third at well over 90 inside the school parking lot. The RD handled, the H-2 went well in straight lines. H-2 didn't turn worth a damn.
I’m going to go try this on my 78 115hp Evinrude tonight. She bogs spits and dies at low idle. Cleaned the carbs and found rubber under the float needle seat AND low speed jet was plugged with the same type of rubber. Was leaking fuel all over and wouldn’t start. After the carb clean, new fuel pump, new fuel lines the motor now sputters and dies. Hoping it’s just a loose connection like you show here. I think I remember looking into the butterfly chamber and saying to myself “ hmm it’s not closed all the way AND it won’t open all the way”. Didn’t do anything about it cause I didn’t see this video yet!! Thank you. Hope this is what fixes “The Little Bogger”.
Good luck mate, I'm sure it will help a lot even if it isn't the only problem.
It seems like the smaller the motor, the more important it is to have the carbs synchronized. I know its bad for all motors but seems there isn't as much wiggle room on the smaller motors. Great job as always Stu!!!
I think you're on the money there, small motors do seem to be more sensitive. About the only motor I could never get running no matter how much I tried was a chainsaw.
Dangar Marine Haha Stu. Its crazy you just said that. I swear to god right now Im in my Dangar Marine shirt cutting a big broken pecan tree with a Dolmar chainsaw that i got running but I can only get it running at a crazy fast idle that scares the crap outta me. Pouring sweat in this hot louisiana weather. Too cool you said that bud!
I knew it lol. Actually I was expecting the bore of one or both of the carb butterfly shaft(s) to be worn. It still great showing how diagnostic leads a person around like that. I once as a teen rebuilt a car engine because I thought I had a head warped.. Turned out a line to the turbo after all of that. No worries though because it really was due at 230k miles I guess.
Was really expecting the manometer to come out for this one. Really informative video, thanks.
Manometers are used with four strokes where you have an intake manifold vacuum to measure. You can use a flow meter on the front of the carburettor though.
@@DangarMarine You're absolutely right :) Been a while between jobs for me.
In this series I learned so so much. Its 1 a.m. and its worth of being so tired. But I couldnt stop watching all the episodes around that little 2 stroke.
Glad you enjoyed. :)
Excellent video - this is exactly what I needed to know how to do on my newly acquired Yamaha!
Thanks mate, glad it helped.
great video just shows how much that can effect the running of it very useful
Awesome video! I truly appreciate your time in making these videos. Thanks!
Thanks mate, you're most welcome. :)
Hi Stu, my oldest son has a small older merc 2 cylinder 110. I think it's a 9. something hp. he brought it over for me to help him change the impeller but has other issues. I will gopro this week for fun.
Good luck with the job! :)
This is gold dust info to the learned outboarder like myself - Thanks 😊👍
Thanks mate, glad it was helpful!
Thanks Stu; What a thorough how to video. very easy to follow. God Bless.
wow, had no idea carb synchronization could cause that lean sneeze condition. I was getting anxious when your last few videos didn't find the issue!
I too was surprised to see what affect it had on this motor. Apparently this particularly motor is very sensitive to carb synchronisation.
What a great series. Thanks for uploading, really enjoyed it
Thanks mate, glad you enjoyed it.
Great video, I enjoyed the whole series on that 2 stroke. thank you!
Thanks Travis, you're welcome. :)
i have a yamaha 40hp 3 cylinder from 1986 with this "sneezing" problem on the third cylinder, it revs up fine but at lower rpm and idle it sneezes.
carbs are clean and reed valves looks good
Another awesome video, glad the motor is running
Bloody excellent series of videos - if only I had access to material like this back in the 1980's when I had my boats. What did we do before the interwebnet, eh??
We paid up the A$$ for some joker to lie to us about replacement parts..
I have learned so much by watching your channel! thank you Sir.
I have a 50 HP Yamaha 2stoke that keeps getting clogged jets. almost immediately after cleaning. I have replaced all fuel lines, filters, fuel pump, and ran it on a separate fuel tank. My next step is to replace the spaghetti gaskets or orings inside the carbs. they have some type of gel stuck to them. it was like this when I bought the boat. have you ever seen these gaskets cause this type of problem?
Once gaskets and o-rings start to disintegrate they can certainly cause these types of problems. It's good that you have changed the fuel lines as these are a big cause of trouble once they get old.
Wish you was in tennessee in usa..we need someone like you here..you care about what you are doing..i see that very easy..did you go to lots of training..or did you educate yourself..
God bless
Love the Yammy 2 strokes,great motors n easy to maintain.
mate why didnt you just sync the carbys in the first place ,,,,JUST KIDDN,, loved the video,,always so informative,,,one of the best videos,,,please keep up the fantastic work...I did have a problem with a slugesh motor,,it was a leaky fuel pump diafram...hopefully we will meet one day as i fish near were you live...take care friend.....cheers Brett
Thanks Brett, glad you've been enjoying the vids. Hope to see you out of the water one day!
Another excellent video and explanation, thanks Stu, John
Thanks John!
Great video and very educational!
great video as always...can'twait for the 40 johnson....love the evinrude johnson omc motors....just can't kill them
Thanks mate, but unfortunately the video on the Johnson is diagnosing why it died...
Dangar Marine lol ok ...well insert foot in mouth lol....I still like them....and still look forward to the great videos...
Very good series!! I am excited for the Johnson 40 videos you mentioned at the end- that's my trusty motor
I’ve got a 40 that’s sneezing badly so fingers crossed this helps
Great diagnostic series 👍
Great series!
Thanks mate.
stu you're the man if you were a little bit closer I would get you to work on my motor but I'm all the way in the US
Send it over via DHL. I'm not sure if UPS or FedEx could get it to Australia.
Anything can happen for a price. ;)
Superb series of videos 👌
Great video. Big help.
Glad it helped. :)
I enjoy your videos!
Thank you!
Nice work Stu.
Thanks Will!
Thank you Stu, I was eagerly awaiting this video. More good work. Greatly appreciated.
I will be down your way in a month or so, where is your workshop, is it at Brooklyn, I am thinking of paying my debt for all the info. Cheers, Bruce.
Hey Bruce. The workshop is just a little bit towards Sydney in Mount Kuring-gai. It would be great to see you. :)
Stu, you had better email me your address and a phone No.
alanvale at gmail dot com and I will send you my details also.
Interestingly my mate lives at Berowra, just next door to Mt Kuring-gai
Cheers mate.
Great job. Keep up the good work.
Thanks Jethro. :)
Great information as always, thanks!
You're welcome John. :)
Awesome Stu. I had no idea that these engines were that sensitive to carburetors not synchronized perfectly. I definitely learned something from watching this. Is it possible to remove the carbs for cleaning and not disturb the sync settings?
I too was surprised how much it upset the motor. I can't imagine things being too far out after putting the carburettors back on.
Thanks Stu.
Welcome. :)
Nice work Stu, Beer time!
Definitely beer o'clock!
Great video.
Just did this to my old Yamaha. Stripped and cleaned the carbs, they always needed damp start to get it going. Put them back together exactly as they were, started it with no damp start (yay) but had this same issue. Followed this video, brilliant, fixed it. Cheers. One question, is it wrong that it runs better with one of the mixture screws screwed all the way in? The other one is 4 half terns out at the moment. Thanks again, brilliant instructions. Keep em coming.
Hey Malcom, it is a bit odd that one is screwed all the way in, it sounds like that is compensating for a problem but if it runs well I wouldn't worry too much.
Dangar Marine. Hi Stu, thanks a lot for your reply. Next time I'm out I'm going to have another play around with the mixture screws just to be sure this is the best setting. Great videos. Cheers
Great, I still don't have a specific date yet but will let you know in due course.
Keep me posted.
grate video Stuart
any chance in the future of a video checking four stroke valve timing
Well, that was easier than I thought it would be. I figured you would break out a mercury carburetor sync tool. But then, I didn't see any vacuum tube ports on the sides of those little Yam's carbs to attach the tubing to.
Hey Stan. No, those vacuum ports are on the intake manifold of four stroke motors, these two strokes go straight into the crankcase.
amazing videos man !
Thanks Jason. :)
Hello,
I have exactly the same engine, 20D 2007 MY and i want to upgrade it to 25hp. From your knowledge, 20D has the same carbs as 25N?
Thank you
thanks so much for the lesson. question: At 8:20 you say motor is hard to start, so you add more air by opening the butterflys. Isn't a closed butterfly the same as a full choke, which makes it richer and easier to start? And what is the choke mechanism? Obviously it worked, but why? Motor was warm from many video takes?
great video :) u planning to do any videos on the tohatsu 50 2stroke automixing? heard they are similar to the yamaha autolube "series"
Thanks Kristian. I do have one in the shop at the moment so I should look at doing a video before it goes.
otimo video, muito obrigado.
Seja bem-vindo
acredito ter conseguido ajustar os carburadores do Yamaha 60 Hp 3 cilindros, graças ao vídeo que você vez.
this same this is happening to my Mercury 40hp 2 cyl. 1 carb.. cleaned carbs and fuel lines, same spark plug issues, same "fix" when one wire pulled.. but I only have one carb..
Do these motors have a vacuum port, to sync that way - like you did in a previous video? I'm assuming no, but wanted to check. In the process of purchasing a service manual.
No, vacuum ports are only on the intake manifold on four stroke motors.
Dangar Marine: Gotcha, thanks!
i notice that the cam roller has a flat spot on it as does mine on my 25hp . is that an indicator of wear or is that flat spot supposed to be there?
A quick question if you have the time, with my V6 2005 150HP mercury 2 stroke, I've noticed it has 3 carbs fitted but i'm assuming each body contains 2 carbs (so 6 all up) that I'd need to sync using this method ? I find your video's to be very informative and your method of presentation makes it easy to understand, and gives me the confidence to tackle this job. Also how would I know if my outboard was running rich ? is it simply by ensuring that the mixture screws are set to factory settings and thats it ?
Hey Dangar Marine .. Your videos are really good ive subbed and subscribed..I Just came home from doing a link and sync on a F150 at YAMAHA MARINE UNIVERSITY in Atlanta USA and my question is that the instructor told us that it would be best to do this in the water or a very least in a bucket.. I was just curious is it would make that much difference with a load on it.. We had to adjust the TPS to Meet the ISC request at around 42 degrees.
THanks for you videos again. MiKe.
Hi Mike. Trust me, you probably know a lot more about these big Yamaha's than I do! This motor doesn't have any idle speed control other than a simple set of mixture and speed screw. These definitely need to be adjusted warm with the motor in the water but I don't imagine it is so important when adjusting the relationship between the butterfly linkages. Would be interested to hear what your teacher thinks though.
I have a 40 2T yamaha. Cleaned carbs. Adjusted idles - starts fine and runs smoothly but as soon as open throttle or push down linkage she cuts out. So my guess is fuel delivery issue so ordered new pump and filter - after this what else could it be ...?
Hey Stu, another great and well made video!!! I am trying to understand how the "out of sync" carbs could have this effect on the motor!?! Obviously it did but can't comprehend fully.
Haven't seen the Green Machine in a while, all good I hope.
Cheers
Good day sir. I'm a fairly new subscriber to your channel. First of all I have to say you your videos have helped me tramendously. I have what I think is a 1988 90 hp 6cyl Mercury outboard with 3 carbs. I have rebuilt the carbs new coils, wires, plugs, compression on cylinders is 150 lbs almost dead on in each cylinder. Number 5 cyl is acting exactly the same as the cylinder in this video. The only things I haven't done that you have in this series. Is the head gasket, and the Reed valves. Before I do that. I wanna time the engine, and sink the carbs. My question is. Does the same procedure apply to my engine as this one. Would the carbs be adjusted the same way, and have never timed an outboard engine before. Any help you could give me, would be extremely helpful. Oh by the way great videos on the electrical set up on the green machine. Got my 76 Marquis wired up perfect thanks to you.
Hi Brian. The principle of the carb sync is the same, I just can't picture what the adjustment options are like on the old Merc. From memory timing adjustment is quite simple on those older Mercs using a timing light.
Getting game again announcing what next weeks video will be about :-)
at about 09:50 is that that an edit double up ?
And I wish the Johnson 50 twin 'link and Sync' was as simple as your engines. The OMC process is very fiddly, and the book states the engine is sensitive to the cylinders being out of sync.
Ron Powell I have an evinrude 48 SPL. It's essentially the same as your Johnson 50. I've seen the sync and link procedure in the manual, and I agree it doesn't look easy! Hoping I never have to do it.
Hmmm, I'd be interested to look through the procedure. Somebody just gave me a Johnson service manual recently. I think that "double up" was just me being repetitive rather than an edit.
Fireship1 - they ARE the same engines other than the cover sticker- well too close to be of any consequence. The difference between the 50 and the 48 is only where the HP rating is measured- 50 at the flywheel, 48 at the prop.
Thank you for the information. Great video as always. Do have a question. Should you tune the carbs with the air box on or off?
I have a Lowe deck boat with a Johnson 150 motor, salt water edition. I live at a small lake in Texas, fresh water, and the lake was to low to put the boat in for about 5 years. Last year I put it in the water and on idle it runs ok, but when I get into the high rpms or pulling a tuber it will sound the hot motor buzzer and starts cutting out big time. I can turn it off and the turn it back on immediately and I'm going full bore for a while then it does it again. Some times it happens pretty quickly and then again it may be quite a while. I have blasted the carbs with the cleaner at the brass front fitting and they seem clear. I have also replaced the water intake impeller. It has a separate tank for the oil and I thought that may have a problem since its set up so long. Do you have any ideas? Thanks and I really enjoy your videos.
Hi Terry, I'm not overly familiar with those Johnsons, but I presume there will be some way to tell if it is an overheat or an oil alarm. If it is an overheat it may be the thermostat stuck closed so even if the pump is good, the water won't be going through the head.
Thanks
Dangar, are you still posting material on the web? Really appreciate how you explain things. I have an Evinrude VRO 140, and I think I have a carburetor throttle linkage issue. Wish me luck! thanks man!
Yes, still posting, but less outboard stuff these days. Good luck!
Your vids are so addicting I binged-watched this yamaha story... and I don't even have a yamaha! But it did bring up a question for my 1995 200hp Evinrude. In order for it to run smoothly, all six carb screws need to be backed off 6 1/2 turns. Seems excessive but it's the only way to get her to run nicely. Think the amount of screw turns are affected by something else so I can save some fuel? Thanks for the knowledge.
I want to sync and tune 3 carbs on a 1966 outboard, and hoped maybe you could clear up some questions I had after watching the video. Appreciate the way you explain things!
You coarsely set the fuel mixture, and then your steps to sync basically boil down to only one concept: make sure the plates are at the same position at the same time. Sure, you also adjusted the amount of open-ness at idle for good idle, adjusted the throttle cam, then readjusted to make sure you can get full throttle, but basically sync is achieved "only" by setting the plates the same. Is that really the gist of it on a 2 stroke?
i.e.e you didn't show more about the fuel mixture screws, and there was no statment that vacuum is the only way to truly achieve balance. Are those steps required as well?
There's nobody I can find to work on my 3 cyl 75hp McCulloch, so I need to understand it well and do it myself! Thanks in advance for any add'l clarification you'd be willing to offer!
Read add'l comments below, that the vacuum method is only for 4 stroke motors.
Dennis, yep, pretty much have the procedure for a two stroke. This vid is on a four stroke, but all the mixture and idle speed stuff is the same th-cam.com/video/bsHCMJnRY9A/w-d-xo.html
You mentioned balance/synchro is different for 2-stroke vs. 4-stroke engines. Why? Isn’t measurable vacuum the same variable for setting air flow and fuel mixture for both types engines, regardless of how the vacuum is regulated (via reeds or valves)? If not, What’s the difference in procedure for synchronizing carbs on 2-strokes?
Can anyone tell me roughly the year and/or model of this 20hp yam. I have one looks same but cant read the id plate. Im looking for carby kits to suit them carbies, any response appreciated.
Hi how are u,,i have 25hp 2 stroke yamaha enduro with one carburettor ,it was running ok but when i cleaned the carb this problem start to happen (backfire and no power at all) hope u can help me
I synchronized my carbs I have a 48 hp envinrude 2 stroke, when start it up does really good but next day when trying to start it up it off again wonder why.
How many turns do you use on the mixture screws for a 75 85hp Johnson. I can't find it anywhere
Start with 2 turns out and tune from there. There isn't an exact amount, if there was they wouldn't need to be adjustable. This vid might help, just ignore the vacuum gauge stuff as it is a two stroke th-cam.com/video/bsHCMJnRY9A/w-d-xo.html
Dangar Marine thanks so much. I love your channel. I'm no longer afraid to try some the repair work myself. Thanks again
Is the mixture settings the same for a 30hp (30D) two stroke Yamaha, 2016
last thing i would of thought of how ever good tip to know.
Yes, it is surprising the effect is had.
Hi Stu. could I use this procedure on my 40 3 cyl. yam. cheers buddy.
Yep, it's pretty much the same thing.
Good job I was going with the left tire next time. Peace tight lines and be safe out there.
Thanks Coop!
thanks
ahaaa.... there IS balance in the universe...hang on where have I heard that before this week ??