After I split and cleaned my carburator s on my GL 500 Honda. Rebuilt the carbs, and took me 6 months of fustration rebuilding so many times. I finally saw your video. Taken it off and cleaned it throughly. Assembled it and fitted to the bike. Guess what. Urrika moment. Thank you so much. Even after 5 years of you making this vid, people profit from you valuable knowledge. Thank you very much.
WOW my friend, you explained SEVERAL issues happening now on my 2000 dyna twin cam 88. Knowledge is power and you are a powerful person! Thank you for sharing it, with us all, and helping save us all time, headache. And money. People like you my friend this world needs more of. God bless you...
I'm currently trying to get an 02 kz1000 running that sat for like 2 1/2 years, pulled carbs out, completely nastiness, floats stuck, the works! your videos have helped a lot for sure, thank you.
Cody you are the man I've had Honda's my whole life and I'm old! I understand the vacuum system on these fuel valves and the one on my 1500 is working good so far but now I understand after you gave that wonderful explanation of what's all involved with that and what to expect! Thank you so much for the videos you are extremely helpful!
I finally have a use for my Vacuum pump that I purchased in order to bleed the brakes on my 4x4 Silverado, and my Yoda Avalon. I did learn how the fuel petcock works, I did not know before watching your video. You did a perfect explanation of how the unit works, and better yet you provided examples of hard to find vacuum leaks and other defective component within the Fuel petcock itself. I now have the confidence to rip into my Katana 600F, this bike has had quirky fuel issues since the day I bought it online used. The bike did not even run when I bought it, me and my friend Mike bomb started the thing for 1/2hr just so I could ride it home, because I did not have a ramp at that moment. I found your explanation very concise on how the unit "should work." And I really enjoyed the part about hard to find leaks in the system, and what to keep a lookout for in defective parts. Thank you for sharing your knowledge. The Katana has had 3 carb tear-downs and a ultrasonic carb cleaning, and untold # of cans of Seafoam. I unloaded the parts Canon at the bike with brand new aftermarket Coils that come with the plug wires, 2nd set of NGK plugs, a salvaged CDI Ignition box. It ran fine for a couple of years, took it to the car wash and this bike has now turned into the money pit. Honestly, I really had no idea how problematic these petcocks were, now since I understand how they work after watching this TH-cam video, I hope to solve the mystery that has stumped bike shops for 5 years now.
Hey bro.. let me just say.. not only are you a beast when it comes to this but no one else explains and shows things to the level of detail that you do and straight to the points.. I appreciate you. I had a scooter for work sit for 3 months and went crazy trying to clean the carb... ended up that my fuel pump/peacock valve wasnt working correctly.. i would get gas sometimes and sometimes i wouldnt get any.. i would get enough to fill the lil plastic filter before the carb but not enough to rum the scooter... took me 3 days to find out i wasnt getting enough gas cuz it looked like i was and the bike ran sometimes for a day and then not turn on... lol $6 fixes my issue... any store wouldve charged me the 40 for carb cleaning and goddknows whta else
Dude you saved me I doubt you’ll see this since the video is so old but my bike was running ok had some backfiring so I changed plugs started her up again then went back changed oil coolant gear oil air filter sub air filter fuel filter put it all back together haven’t been able to get it to start didn’t even know my petcock pulled a vacuum the manual says something has to be clogged so I’ve been blowing everything out thought maybe the fuel line was air locked pumped fuel into the line by hand was about to give up and take it in and just found this video you sir are a god damn hero
Great video! I have a go kart that is leaking fuel out of the exhaust, and you have further reaffirmed me that it is this device along with the carb floats. I noticed when trying to start it up, fuel leaks through the vacuum hose. I also noticed that when the go kart isn’t even running, it is leaking fuel out of the exhaust, indicating the carb floats are also a culprit. Thank you so much for this! Very informative!
thank you man iv'e been fighting with card setup issues for 4 days just to find out my fuel tap is ''broken'' and i'm seeing the same symptoms you have described runs fuel out for a bit then stops, i'm going to replace it tomorrow for one that works. thanks again for the help
I replaced the leaking petcock diaphram spring etc with a kit. Now i have no gas getting to carbs? Blew and sucked in the vacuum line going back to motor , no blockage. I did replaced the strainer with a new one that had a larger o-ring on it? Thinking carb trouble ? Thank you for your help you do a great job for us dummies !!!
I see this video is 5 years old, and after taking apart Mt bike and carbs 8 times I was close to scrapping the bike, until I had a funny feeling it was the fuel tap and after watching this I am pretty certain it is, I've ordered the parts so time will tell, Thanks alot for the video
Awesome man..Mine just started running out of gas when the tank got down to about 1/3 filled. I took it apart and stretched the spring and it seems to be working. More testing needed though. It's a 2002 Honda Nighthawk 750.
Dude , I appreciate thus video so much, I just rebuild an 500vt and got it back together and the petcock leaking bad. Tried to clean and repair it but everything looks good. Now I know I just need to replace it.
I suspect this may be my problem on a Suzuki, I wanted to see how the inside of them worked, not a lot out there, the factory diagrams are not great. From the moment I got this bike I was confused why it had on, pri and res but not a off position. Started leaking gas the first time I filled the gas tank. I noticed the second tube when taking the carb out to send it off to be rebuilt and saw gas flowing from both tubes. Thought nothing of it until I saw the factory manual did say it was a vacuum hose only so that was my first clue. Great video. Still helping people 4 years later.
Man! I wish you were my next door neighbor. I love how you teach this stuff. I’ve done several kinds of fixes successfully from your vids. Well, I guess you are my next door neighbor in that way. Thanks for the great content.
Yup, leaking peacock on my 2004 VTR1000! I kept smelling stale gas in the garage. Hadn’t ridden the bike for a while and started to look around the engine and found it dripping gas from the small peacock vent nipple. New peacock $275, repair kit $25. Saw your video which supported my assumption of the problem. I keep my tanks filled with AvGas to keep the ethanol from corroding the carbs. Still think emulsion tubes in carbs could be slightly plugged... time to disassemble carbs and clean emulsion orifice with .009 guitar string!
I'm having this problem with my 96 F3. The vacuum has been changed to a standard flow. So right at the end if your video you said it! Gas getting into my valves n into crank case. So I've done everything else... ECT. My wife said clean the damn carbs. The bike was sitting for over a year. I was trying not to go through all this cause I just wanna scream the BIKE! So looking like carbs are coming off! Thanks so MUCH! I've been working on n racing over half my life. I'm 36 so... I'LL let you know brother! Thanks again
Great job explaining how everything works, what properly working vs failure looks like, and how to test each case. My vacuum port was somehow completely clogged. Thanks!
Thanks very much for the tip. I paid €78 for the part with the broken membrane. The valve was located on the right side of my super Magna, half way cylinder 3. It was easier to suck it without the tube, since the other end was difficult to reach. Thanks again.
Thanks, I'm helping my French neighbour by re- conditioning the carbs in his Yamaha FJ 600. I rebuilt them, but when put back together, there was a fuel leak by the fuel prime- on-off lever. I'm an ex road racer, so not completely stupid, but needed some pointers as to the vacuum and "Primer" workings. Pretty sure that tomorrow will get it running ok....... will let you know.
Thank you, You mentioned it backfiring all the time when running and actually I noticed that I forgot to turn off the fuel so when I went to try to start it again. it was flooded SO.......I think I'm not holding vacuum. I'm going to try replacing it. simple and cheap fix. Hopefully that works. Thanks again
Mine isn't shutting off the fuel. So over night fuel has leaked onto the ground. Not much but enough to smell it and the bike starts half flooded. Carbs where rebuilt two years ago. I used your video to help sync the carbs. Thanks for the info.
Lucky i found it...i basically placed the spring down the bottom cause when i opened the petcock...spring jumped out... didn't know where suppose to be... your explanation show exactly location of spring 🙏
Great relevance for this. I attempt to ride nearly everyday and all year long but am always vigilant about this little bugger. I replacement for my 97 1500 Valk is about 50 bucks, an easy amount to spend in light of the havoc it can create if it fails. Well done video, right pace, good framing, spot on.
Very informative, just had a huge leak from a petcock on a bike that had been sitting for years. I cleaned it tonight but am unable to test it yet. I think it had the final scenario you were talking about, just covered in gunk and got stuck open. even if it gets stuck again tomorrow, at least I will understand why as I buy a new diaphragm. Nice job!
just got my first bike yesterday. 1985 Yamaha Virago/Maxim 750. needs tlc but it was a good price for $500. the guy said it had a clogged petcock. I had already looked up the petcock stuff and knew it was vacuum operated. your knowledge on this however, earned a sub from me xD
Thank you,, thank you, thank you for taking the time to help. It was just what I needed, I had everything, gas in the floor, did not start, and finally the petcock with a tear that I found thanks to you. .
Really informative. Thanks for this. I have been suffering a "niggle" on my 2000 Hornet - after riding for about 20 minutes it wants to cut out at idling speed. If I stop for a while i recovers. An experience mechanic suggested that an electrical problem affected by heat would most likely be the problem, but couldn't fix it. Having just fitted a clear fuel filter in the fuel line, I can see that fuel flow is the problem. I'm going to investigate the fuel tap and diaphragm. Cheers.
Great video! Struggling to get my 2001 Valkyrie to run. Starts and runs easily and fine when I inject starter fluid. Tested vacuum valve, but did apply vacuum for an extended period. Back to the garage!!! LOL!
Code, thanks brother. Trying to fix a scooter for my son and this is a big piece of the puzzle. Thinking of replacing the whole system with a Honda oem electric fuel pump and a pulse doohicky from probld.
Good info but I wish you would have covered the testing a bit more thoroughly. I have two of them that won't shut off on a 1980 Yamaha XS850SG. I replaced all of the diaphragms and o-rings but that didn't change a thing. Showing how they are assembled would be very helpful!
Thank you for helping me find the problem!! The diaphragm failed just where you showed in the video! I would never have found the leak if you had not showed where to look!
Thanks cody. I have gas coming thru the vacuum hose into the #2 carb and its running rough and the #2 cylinder header pipe is not as hot as the others. Now i know thanks to you i shouldn't have fuel in the vacuum hose. I ordered a rebuild kit for the fuel valve. I hope this solves the problem.
Great video you helped me solve my problem with my cbr900rr. Slide note I purchased a new/rebuild petcock on ebay and it failed within 20 miles and left me stranded. From now on I will only use genuine Honda parts.
Thanks dude, you just really helped me out with trying to work out why my 1500 Valkyrie is overflowing petrol after a carb rebuild. My petcock was completely rotted out. Not a split in the diaphragm, there wasn't even a diaphragm, and the vacuum hose wasn't connected either. There was a shit load of backfiring under de-acceleration and not running on all 6 cylinders. That said, the mixtures on the entire left side were way out too. Your video has been very helpful.
Thank you I got a 50cc scooter TaoTao and I've been fighting this problem for a couple of days trying to figure out what to do actually I think the petcock is okay I think my vacuum hoses hook to the wrong spot I subscribed and I'll continue to listen thank you again Chuck
It’s like a carburetor had intercourse with a master cylinder..and we now have carb junior. That’s insane you had that many in a month. My bro...I took mine off I’ve heard far too many bad things..needless to say the recall on them. Good video btw you always come through. I like that you break down the entire thing..some of us are new to this..I appreciate the time and effort. Thanks my man
Thanks for putting this out there. People need to know about these vacuum valves, and more generally the evil ethanol works on their bikes. I've got an old XS11 that had four carbs rebuilt right before I bought it. Bad cocks (due partly to gasahol) are why I had to rebuild them all again as soon as I got started rehabbing her.
The video is really informative and I'd like to thank you so much bro,but please we need more illustration and hands-on next time, I have currently the exact same problem on my 04 Honda VTX 1300c and this stupid fuel valve is leaking 😢
Great information. I have a 1980 Suzuki GS550L. Works great but leaks Gass all over. Problem is I can't find a new replacement for this year make and model. Any suggestions where I can buy one? Thanks for the help
Very informative and educational. Thanks so much bro! I have 2007 Honda Shadow Aero vt750c and in warmer weather it will quit supplying fuel after about 17 - 20 miles. But after stopping for 3-5 minutes it starts and runs great for that many or more miles. But doesn't do it in cooler temperatures. I'm guessing the vacuum line is getting warm and collapsing. I think I need a new line, diaphragm or both. Just want to know where it's routed and if I need to remove the seat and tank to repair it. Other than that, it's top notch and I ride pretty much daily. Again, thanks so much for sharing your knowledge on everything.
Thank you! my 1999 Honda CBR900rr Petcock diaphragm went bad thanks to you I would’ve never checked that, it was driving me nuts I pulled the carburetors cleaned them, change the spark plugs check the coils it was driving me crazy then after watching this video I checked the gas tank petcock valve -WHAMO- damn that was it. 👍👍
Thank goodness I found this video, I was losing the will to live coz I couldn’t remember which order the diaphragm and insides went back together. Really helpful, you have another new and grateful subscriber, thanks for sharing Cheers from the GB Col 🇬🇧👍🇬🇧👍🇬🇧
Great advice... Im trying to trouble shoot a 98 blackbird XX. Running OK upto 80mph...100mph it dies... Like it's running out of fuel... Pull over and it starts fine and rides...
I have a '94 Honda Magna. I got the carbs rebuilt and upon reassembly, I can't get fuel to flow through the vaccuum fuel valve. I tried replacing it with a new fuel valve, but I can't get fuel to flow through that one either. I have found that I can replace the vaccuum fuel valve with a ball valve(basically like a second petcock switch) and that works. I can start the bike and it rides just fine, but I'd rather have the correct part on. I've tried putting the vacuum fuel valve back on after confirming that that's where the fuel flow was stopping, but I still can't get it to pass through.
Thanks for the info. I started up my '82 Yamaha Maxim xj550 after a few months & even though I can see a small leak coming from a boot off the carb there is a non-stop flow coming out of the bottom of the motor & I'm gonna need all the info I can get. I just really wanted to get out of the house & ride my bike during the Shelter-In-Place order so I don't lose my mind
i learned something new. my 82 kz, vacuum operated, mikuni carbs. i have yet to pull the carbs off. turned fuel valve on and fuel came out my intake pods and overflow hoses. ill check my oil for gas.
Great video and awesome knowledge transfer! The video is a few years old but I really hope someone can help. My 1986 Nighthawk 450 shuts down when I hit 55+ mph for a few minutes. The guy I bought it from did a thorough clean of the carbs and other parts, so is it possible he missed this? Could this valve be the problem?
I think a fuel valve with just off, on and reserve is better. Less failure points and you can still stop the fuel flow to keep the engine and carbs safe. This is still a great video and helpful for my current kawasaki KE175 with vacuum valve problems.
I have a 750F2 (UK version of the Nighthawk). I stripped the vacuum operated fuel tap prior watching this video. I wish I'd see it before to know what was going on. But I did find a load of dirt in the fuel tank filter though, which sits around the brass 'reserve stalk' - worth pulling out if you intend the diaphram examination.
Great description of the fuel cock. I just discovered I’m missing a spring seat between the spring and rubber diaphragm. Thanks for the great info. Btw, my 1984 Nighthawk S was sitting in garage for 15 years (last insured - 2006) and it started up after replacing old fuel and battery. Now I will take your advise, “Ride your bike”.
Hey, I have a 1996 Honda Magna and it is leaking gas out from underneath the vacuum pump. What do I do? I know you briefly mentioned it in your video but can you explain more in depth please. Great video by the way. Thank you
When at 9:30 you said there was a recall on the Honda Shadow 750C/C2... I looked it up and sure enough, year 2007-2008. They're stated reason is drip, but it's no drip, this part is defective because the valve isn't working right. Maybe it drips too, as a result, who knows, but my net results is sometimes it leaves the fuel line bone dry when you're turning the bike over and over forever.
Had the "sticking" problem on a Suzuki GS500 due to contaminated fuel (due to corrosion in the tank) which I had no idea what was going on ; I now know exactly what happened back then ! Thx
Thank you for the video! I have a cb650 SC 1984 nighthawk. I took the airbox out and put some carb air pod filters on them. I can't get my bike to fire. It spits and tried but my buddy told me I need to get my carburetor with bigger ports to allow more gas into the carbs. Do you know what he is talking about and do you have any content highlighting this issue?
Hi great video I've just replaced both diaphragms and spring on my 1983 GL650 yet fuel is still pouring out of the petrol tap when the engine isn't running.
Thank you for your video, very informative. I have a 1972 that uses vacuum fuel valve, can a vacuum leak also cause number 2 cylinder to leak fuel out of the Overflow after engine shuts off?
Thanks for this video. I have a 1981 Honda CB900c with a automatic fuel valve. It's been bipassed because the parts are unavailable. Is it worth finding a repair kit for it and do you know where I can find one?
Great video, brother! Had a problem like that and changed for a new pump. However after changing the engine oil it still smelled of gas. Is that normal?
Well there’s another part to add to the list at the next service. My Shadow runs great, but I was testing this by applying vacuum as you describe, and it doesn’t hold vacuum. I have to wonder if that small vacuum leak would cause some intermittent anomalies on the bike. At least you can buy just the vacuum diaphragm piece!
My CB600f Hornet has a big blob of clay or similar inside the fuel valve blocking the vacuum pipe. I guess that the diaphragm tore and somebody decided to do some serious bodge job on it! Bike did run fine for a few hundred miles after I bought it, however then it started running on three, breaking down etc. So I'm fixing it up to run again. The more I take it apart the more bodges I'll find I bet!
Geez, it's nearly 4 years ago, I hope you can see this comment. Firstly I speak in metric but I think you'll get the gist...I have a case where the fuel stops getting to the carb when the tank gets low. My cruiser, a GV250, has a 14L tank. I should be doing around 350 to 400kms but by 190 to 230 kms, it could start to cut out. Spluttering, backfiring, the works therefore when that happens or just before it does, I have to switch to the reserve tank. Yesterday just to check and after having to switch to the reserve, I emptied the fuel out to see how much I had left and found that I had at least 3.5L left which should take me for another 100 kms I think. I have taken it to the mechanics and after $$$, they can't find anything wrong. Myself I have emptied the tank and removed to clean and see, and also the fuel valve..and nothing, mind you I'm no mechanic. After 2-3 years with this problem, I think I may have found the problem and it may happen that the pressure of a full tank allows the fuel to the carb, VIA a Vacuum fuel pump, seamlessly, until the pressure gets low and then I have this problem. Would I be right to think this? Anyway thanks for the video.
Replacing my 90's Suzuki DR125 Pet cock because of leaking. Found an extra tube going back to the carb ! !~ So, looks like I have a vacuum fuel valve (WHO WOULD KNOW !). Anyway, will dig into it and see if I can find a problem with the Vacuum fuel shutoff. Would be nice to not have to buy an entire new Pet Cock assembly. Thanks for the nice easy to understand video !
Awesome video..I have a 1996 Honda 750 Magna..Is it necessary to suck on the vacuum hose to allow the carb float bowls to fill with gas before the engine is running? I replaced both the on off petcock and the auto valve..I opened the drain plug on each carb and got mostly gas stabilizer. The bike just doesnt seem to be getting gas to the carb..The spark plugs are dry if you know what I mean..Thanks..hope all is well..
Great info. I wish this would help me solve my issue, but at least i learned a few thingsd... My Yamaha only runs on "reserve" (the reserve is a button on handlebars, the petcock itself only has "on" and "off", there is not "prime" either). Only thing I did was replace the o-rings and my petcock doesnt leak now (the reason why i took it apart), but now the bike only runs with the switch on "reserve". Any suggestion what I did wrong?
wow amazing and educational video much appreciated it helped me alot. I have a question Where can I find diaphragm for 1982 Honda CB900 Custom ? is it oem part or can it be purchased online after market ? Thank you again.
Just watched video great information ,but needed info on a vacuum fuel valve leaking out of its bottom over flow tube? which was briefly mentioned. Does this mean it is stuck open?
Dude I have been stumped on why my bike is running like shit (it’s a 89 transalp ) I think you just helped me figure it out. The cylinder it pulls vaccum from keeps fouling out and running like shit , I’m going to run it off of a gravity fuel bottle and see
hey friend fuel valves that you demonstrate is same with the fuel valves that i have for my cb400, but every time i turn on the bike there's a fuel leaking in the tiny whole that you mention in your video. is sign of bad valves.? or it's normal. thank you
Hi, Thank you for this helpful video. I have a 50CC scooter that uses a vaccuum valve and as it was not starting and no fuel seemed to be flowing from the tank I suspected it was the valve, I did your suck test on it and it is not pulling any vaccuum at all. So thanks for the helpful video.
Thanks Cody. Very informative. My 86 Honda scooter intermittently bogs like it isn't getting enough gas. I've cleaned the carbs twice but still have the problem. I sucked on the vacuum line and fuel dribbles out of the petcock. It seems like low flow. I may have a torn diaphragm. My petcock is probably 33 years old. I will investigate further. What do you think about a cheap Chinese petcock replacement?
I never even heard of a vacuum fuel petcock until mine quit working. It's a bad design, i am going to replace it with a normal on-off-reserve valve. Whats the point of vacuum fuel valve anyway? Just so you don't forget to turn off the gas?
Great video! What about. Fuel reserve on petcock not working just bought a 1982 cb900f runs super strong. Bike started chugging so I flipped it to reserve bike stalled. Pulled over still had half gallon or so in tank. Put 2 gallons in started right up!! Think valve is bad or just the reserve filter clogged????
Great video man, sure did learn alot.. I have a 1996 Vulcan 800.. it's also a vacuum petcock, and I get gas coming out the exhaust when it sits for a while. After watching your video I checked and found that my Petcock flows gas when set to ON, AND RESERVE.. (WITH THE ENGINE TURNED OFF)...what do you think about that?? Any information from you, or anyone out there would greatly appreciate..
![No more vacuum fuel pump problems! GY6 Won’t start: FIX! [PROBLD PULSER UNIT]](http://i.ytimg.com/vi/I_k3jgNswCU/mqdefault.jpg)
Dude- people like you are making the internet great again! Thanks for sharing your knowledge out to us plebes.
Couldn't agree more ;-)
After I split and cleaned my carburator s on my GL 500 Honda. Rebuilt the carbs, and took me 6 months of fustration rebuilding so many times.
I finally saw your video. Taken it off and cleaned it throughly.
Assembled it and fitted to the bike.
Guess what. Urrika moment.
Thank you so much. Even after 5 years of you making this vid, people profit from you valuable knowledge.
Thank you very much.
WOW my friend, you explained SEVERAL issues happening now on my 2000 dyna twin cam 88.
Knowledge is power and you are a powerful person!
Thank you for sharing it, with us all, and helping save us all time, headache. And money. People like you my friend this world needs more of. God bless you...
I'm currently trying to get an 02 kz1000 running that sat for like 2 1/2 years, pulled carbs out, completely nastiness, floats stuck, the works! your videos have helped a lot for sure, thank you.
+NorthJorgie89 That's awesome man! No problem!
Cody you are the man I've had Honda's my whole life and I'm old! I understand the vacuum system on these fuel valves and the one on my 1500 is working good so far but now I understand after you gave that wonderful explanation of what's all involved with that and what to expect! Thank you so much for the videos you are extremely helpful!
I finally have a use for my Vacuum pump that I purchased in order to bleed the brakes on my 4x4 Silverado, and my Yoda Avalon. I did learn how the fuel petcock works, I did not know before watching your video. You did a perfect explanation of how the unit works, and better yet you provided examples of hard to find vacuum leaks and other defective component within the Fuel petcock itself.
I now have the confidence to rip into my Katana 600F, this bike has had quirky fuel issues since the day I bought it online used. The bike did not even run when I bought it, me and my friend Mike bomb started the thing for 1/2hr just so I could ride it home, because I did not have a ramp at that moment. I found your explanation very concise on how the unit "should work." And I really enjoyed the part about hard to find leaks in the system, and what to keep a lookout for in defective parts. Thank you for sharing your knowledge. The Katana has had 3 carb tear-downs and a ultrasonic carb cleaning, and untold # of cans of Seafoam. I unloaded the parts Canon at the bike with brand new aftermarket Coils that come with the plug wires, 2nd set of NGK plugs, a salvaged CDI Ignition box. It ran fine for a couple of years, took it to the car wash and this bike has now turned into the money pit.
Honestly, I really had no idea how problematic these petcocks were, now since I understand how they work after watching this TH-cam video, I hope to solve the mystery that has stumped bike shops for 5 years now.
Hey bro.. let me just say.. not only are you a beast when it comes to this but no one else explains and shows things to the level of detail that you do and straight to the points..
I appreciate you. I had a scooter for work sit for 3 months and went crazy trying to clean the carb... ended up that my fuel pump/peacock valve wasnt working correctly.. i would get gas sometimes and sometimes i wouldnt get any.. i would get enough to fill the lil plastic filter before the carb but not enough to rum the scooter... took me 3 days to find out i wasnt getting enough gas cuz it looked like i was and the bike ran sometimes for a day and then not turn on... lol $6 fixes my issue... any store wouldve charged me the 40 for carb cleaning and goddknows whta else
Dude you saved me I doubt you’ll see this since the video is so old but my bike was running ok had some backfiring so I changed plugs started her up again then went back changed oil coolant gear oil air filter sub air filter fuel filter put it all back together haven’t been able to get it to start didn’t even know my petcock pulled a vacuum the manual says something has to be clogged so I’ve been blowing everything out thought maybe the fuel line was air locked pumped fuel into the line by hand was about to give up and take it in and just found this video you sir are a god damn hero
Great video! I have a go kart that is leaking fuel out of the exhaust, and you have further reaffirmed me that it is this device along with the carb floats. I noticed when trying to start it up, fuel leaks through the vacuum hose. I also noticed that when the go kart isn’t even running, it is leaking fuel out of the exhaust, indicating the carb floats are also a culprit. Thank you so much for this! Very informative!
thank you man iv'e been fighting with card setup issues for 4 days just to find out my fuel tap is ''broken'' and i'm seeing the same symptoms you have described runs fuel out for a bit then stops, i'm going to replace it tomorrow for one that works.
thanks again for the help
I replaced the leaking petcock diaphram spring etc with a kit. Now i have no gas getting to carbs? Blew and sucked in the vacuum line going back to motor , no blockage. I did replaced the strainer with a new one that had a larger o-ring on it? Thinking carb trouble ? Thank you for your help you do a great job for us dummies !!!
I see this video is 5 years old, and after taking apart Mt bike and carbs 8 times I was close to scrapping the bike, until I had a funny feeling it was the fuel tap and after watching this I am pretty certain it is,
I've ordered the parts so time will tell,
Thanks alot for the video
Hope it fixes the issue brother!
@@TheMotorcycleMD I can confirm the issue was the tap so I appreciate your video and the further aggro it saved me
Awesome man..Mine just started running out of gas when the tank got down to about 1/3 filled. I took it apart and stretched the spring and it seems to be working. More testing needed though. It's a 2002 Honda Nighthawk 750.
Dude , I appreciate thus video so much, I just rebuild an 500vt and got it back together and the petcock leaking bad. Tried to clean and repair it but everything looks good. Now I know I just need to replace it.
I suspect this may be my problem on a Suzuki, I wanted to see how the inside of them worked, not a lot out there, the factory diagrams are not great. From the moment I got this bike I was confused why it had on, pri and res but not a off position. Started leaking gas the first time I filled the gas tank. I noticed the second tube when taking the carb out to send it off to be rebuilt and saw gas flowing from both tubes. Thought nothing of it until I saw the factory manual did say it was a vacuum hose only so that was my first clue. Great video. Still helping people 4 years later.
Man! I wish you were my next door neighbor. I love how you teach this stuff. I’ve done several kinds of fixes successfully from your vids. Well, I guess you are my next door neighbor in that way. Thanks for the great content.
Yup, leaking peacock on my 2004 VTR1000! I kept smelling stale gas in the garage. Hadn’t ridden the bike for a while and started to look around the engine and found it dripping gas from the small peacock vent nipple. New peacock $275, repair kit $25. Saw your video which supported my assumption of the problem. I keep my tanks filled with AvGas to keep the ethanol from corroding the carbs. Still think emulsion tubes in carbs could be slightly plugged... time to disassemble carbs and clean emulsion orifice with .009 guitar string!
I'm having this problem with my 96 F3. The vacuum has been changed to a standard flow. So right at the end if your video you said it! Gas getting into my valves n into crank case. So I've done everything else... ECT. My wife said clean the damn carbs. The bike was sitting for over a year. I was trying not to go through all this cause I just wanna scream the BIKE! So looking like carbs are coming off! Thanks so MUCH! I've been working on n racing over half my life. I'm 36 so... I'LL let you know brother! Thanks again
Great job explaining how everything works, what properly working vs failure looks like, and how to test each case. My vacuum port was somehow completely clogged. Thanks!
Thanks very much for the tip.
I paid €78 for the part with the broken membrane.
The valve was located on the right side of my super Magna, half way cylinder 3.
It was easier to suck it without the tube, since the other end was difficult to reach.
Thanks again.
Thanks, I'm helping my French neighbour by re- conditioning the carbs in his Yamaha FJ 600. I rebuilt them, but when put back together, there was a fuel leak by the fuel prime- on-off lever. I'm an ex road racer, so not completely stupid, but needed some pointers as to the vacuum and "Primer" workings. Pretty sure that tomorrow will get it running ok....... will let you know.
Thank you, You mentioned it backfiring all the time when running and actually I noticed that I forgot to turn off the fuel so when I went to try to start it again. it was flooded SO.......I think I'm not holding vacuum. I'm going to try replacing it. simple and cheap fix. Hopefully that works. Thanks again
Mine isn't shutting off the fuel. So over night fuel has leaked onto the ground. Not much but enough to smell it and the bike starts half flooded. Carbs where rebuilt two years ago. I used your video to help sync the carbs. Thanks for the info.
Lucky i found it...i basically placed the spring down the bottom cause when i opened the petcock...spring jumped out... didn't know where suppose to be... your explanation show exactly location of spring 🙏
Great relevance for this. I attempt to ride nearly everyday and all year long but am always vigilant about this little bugger. I replacement for my 97 1500 Valk is about 50 bucks, an easy amount to spend in light of the havoc it can create if it fails. Well done video, right pace, good framing, spot on.
Very informative, just had a huge leak from a petcock on a bike that had been sitting for years. I cleaned it tonight but am unable to test it yet. I think it had the final scenario you were talking about, just covered in gunk and got stuck open. even if it gets stuck again tomorrow, at least I will understand why as I buy a new diaphragm. Nice job!
just got my first bike yesterday. 1985 Yamaha Virago/Maxim 750. needs tlc but it was a good price for $500. the guy said it had a clogged petcock. I had already looked up the petcock stuff and knew it was vacuum operated. your knowledge on this however, earned a sub from me xD
Thank you,, thank you, thank you for taking the time to help. It was just what I needed, I had everything, gas in the floor, did not start, and finally the petcock with a tear that I found thanks to you. .
So helpful Cody - I did not know this vacuum valve could cause so many issues.
Great video Sir.
A couple of years late to the party but this video just answered my question about the extra hose ports on my petcock and my carbs. Thank you.
Really informative. Thanks for this. I have been suffering a "niggle" on my 2000 Hornet - after riding for about 20 minutes it wants to cut out at idling speed. If I stop for a while i recovers. An experience mechanic suggested that an electrical problem affected by heat would most likely be the problem, but couldn't fix it. Having just fitted a clear fuel filter in the fuel line, I can see that fuel flow is the problem. I'm going to investigate the fuel tap and diaphragm. Cheers.
Great video! Struggling to get my 2001 Valkyrie to run. Starts and runs easily and fine when I inject starter fluid. Tested vacuum valve, but did apply vacuum for an extended period. Back to the garage!!! LOL!
Code, thanks brother. Trying to fix a scooter for my son and this is a big piece of the puzzle. Thinking of replacing the whole system with a Honda oem electric fuel pump and a pulse doohicky from probld.
Good info but I wish you would have covered the testing a bit more thoroughly. I have two of them that won't shut off on a 1980 Yamaha XS850SG. I replaced all of the diaphragms and o-rings but that didn't change a thing. Showing how they are assembled would be very helpful!
KAWASAKI VN 8OO this vid has totaly explained the vacum petcock that is causing fuel to flow from the over flow pipes when not running. Great vid
Hey dude thanks for the info, I have a 1994 CB500 with the same issues. Thanks to you I know what to do. Awesome.
Thank you for helping me find the problem!! The diaphragm failed just where you showed in the video! I would never have found the leak if you had not showed where to look!
Thanks cody. I have gas coming thru the vacuum hose into the #2 carb and its running rough and the #2 cylinder header pipe is not as hot as the others. Now i know thanks to you i shouldn't have fuel in the vacuum hose. I ordered a rebuild kit for the fuel valve. I hope this solves the problem.
Great video you helped me solve my problem with my cbr900rr. Slide note I purchased a new/rebuild petcock on ebay and it failed within 20 miles and left me stranded. From now on I will only use genuine Honda parts.
+Paul Sterling The best advice you can ever give someone 🤙🤙
I think this is what’s wrong with my vtx. It’s been backfiring and now it acts like it’s not getting fuel. Thanks so much for the info!
Thanks dude, you just really helped me out with trying to work out why my 1500 Valkyrie is overflowing petrol after a carb rebuild. My petcock was completely rotted out. Not a split in the diaphragm, there wasn't even a diaphragm, and the vacuum hose wasn't connected either. There was a shit load of backfiring under de-acceleration and not running on all 6 cylinders. That said, the mixtures on the entire left side were way out too. Your video has been very helpful.
Thank you I got a 50cc scooter TaoTao and I've been fighting this problem for a couple of days trying to figure out what to do actually I think the petcock is okay I think my vacuum hoses hook to the wrong spot I subscribed and I'll continue to listen thank you again Chuck
This dude made the perfect video where he showed the inside of the vacuum diaphragm, i mean how it works!!!
It’s like a carburetor had intercourse with a master cylinder..and we now have carb junior. That’s insane you had that many in a month. My bro...I took mine off I’ve heard far too many bad things..needless to say the recall on them. Good video btw you always come through. I like that you break down the entire thing..some of us are new to this..I appreciate the time and effort. Thanks my man
Thanks for putting this out there. People need to know about these vacuum valves, and more generally the evil ethanol works on their bikes. I've got an old XS11 that had four carbs rebuilt right before I bought it. Bad cocks (due partly to gasahol) are why I had to rebuild them all again as soon as I got started rehabbing her.
+Jeff Puskarich Knowledge is power! (and a money saver) 🤙
Jeff Puskarich I
The video is really informative and I'd like to thank you so much bro,but please we need more illustration and hands-on next time, I have currently the exact same problem on my 04 Honda VTX 1300c and this stupid fuel valve is leaking 😢
Best motorcycle mechanic on the internet!
Great information. I have a 1980 Suzuki GS550L. Works great but leaks Gass all over. Problem is I can't find a new replacement for this year make and model. Any suggestions where I can buy one? Thanks for the help
Very informative and educational. Thanks so much bro! I have 2007 Honda Shadow Aero vt750c and in warmer weather it will quit supplying fuel after about 17 - 20 miles. But after stopping for 3-5 minutes it starts and runs great for that many or more miles. But doesn't do it in cooler temperatures. I'm guessing the vacuum line is getting warm and collapsing. I think I need a new line, diaphragm or both. Just want to know where it's routed and if I need to remove the seat and tank to repair it. Other than that, it's top notch and I ride pretty much daily. Again, thanks so much for sharing your knowledge on everything.
Great information, very helpful. It helped me to get my bike running perfectly. I did not imagine that that was the problem.
I googled fuel issues for my older harley sportster and this video came up.
Very informative, thank you.
Great video. Have have no end of trouble sorting out a fuel drowning problem until I came across your footage. Thank you.
Thank you! my 1999 Honda CBR900rr Petcock diaphragm went bad thanks to you I would’ve never checked that, it was driving me nuts I pulled the carburetors cleaned them, change the spark plugs check the coils it was driving me crazy then after watching this video I checked the gas tank petcock valve -WHAMO- damn that was it. 👍👍
Thank goodness I found this video, I was losing the will to live coz I couldn’t remember which order the diaphragm and insides went back together.
Really helpful, you have another new and grateful subscriber, thanks for sharing
Cheers from the GB
Col 🇬🇧👍🇬🇧👍🇬🇧
👌🏻👌🏻
Great video, Cody! Well explained, extremely informative. Thank you for taking the time to educate.
What is a pallet screw? And how do you adjust it. Thanks for your help.
Great advice... Im trying to trouble shoot a 98 blackbird XX. Running OK upto 80mph...100mph it dies... Like it's running out of fuel... Pull over and it starts fine and rides...
I have a '94 Honda Magna. I got the carbs rebuilt and upon reassembly, I can't get fuel to flow through the vaccuum fuel valve. I tried replacing it with a new fuel valve, but I can't get fuel to flow through that one either. I have found that I can replace the vaccuum fuel valve with a ball valve(basically like a second petcock switch) and that works. I can start the bike and it rides just fine, but I'd rather have the correct part on. I've tried putting the vacuum fuel valve back on after confirming that that's where the fuel flow was stopping, but I still can't get it to pass through.
Thanks for the info. I started up my '82 Yamaha Maxim xj550 after a few months & even though I can see a small leak coming from a boot off the carb there is a non-stop flow coming out of the bottom of the motor & I'm gonna need all the info I can get. I just really wanted to get out of the house & ride my bike during the Shelter-In-Place order so I don't lose my mind
i learned something new. my 82 kz, vacuum operated, mikuni carbs. i have yet to pull the carbs off. turned fuel valve on and fuel came out my intake pods and overflow hoses. ill check my oil for gas.
Thanks for sharing your knowledge. I’ve had this issue before and never really understood how the whole vac. Thing worked. Thanks again !
Great video and awesome knowledge transfer! The video is a few years old but I really hope someone can help. My 1986 Nighthawk 450 shuts down when I hit 55+ mph for a few minutes. The guy I bought it from did a thorough clean of the carbs and other parts, so is it possible he missed this? Could this valve be the problem?
I think a fuel valve with just off, on and reserve is better. Less failure points and you can still stop the fuel flow to keep the engine and carbs safe. This is still a great video and helpful for my current kawasaki KE175 with vacuum valve problems.
This was great and EXACTLY what I've been dealing with on my 2005 Shadow! Thank you for the information!!!
Aero?
I have a 750F2 (UK version of the Nighthawk). I stripped the vacuum operated fuel tap prior watching this video. I wish I'd see it before to know what was going on. But I did find a load of dirt in the fuel tank filter though, which sits around the brass 'reserve stalk' - worth pulling out if you intend the diaphram examination.
Thank you man, this is the prob, i had on my cbr900rr sc33, now its done thanks to you
+Dalum Pige Fodbold 🤙🤙 Nice fix bro!
Great description of the fuel cock. I just discovered I’m missing a spring seat between the spring and rubber diaphragm. Thanks for the great info. Btw, my 1984 Nighthawk S was sitting in garage for 15 years (last insured - 2006) and it started up after replacing old fuel and battery. Now I will take your advise, “Ride your bike”.
Hey, I have a 1996 Honda Magna and it is leaking gas out from underneath the vacuum pump. What do I do? I know you briefly mentioned it in your video but can you explain more in depth please. Great video by the way. Thank you
When at 9:30 you said there was a recall on the Honda Shadow 750C/C2... I looked it up and sure enough, year 2007-2008.
They're stated reason is drip, but it's no drip, this part is defective because the valve isn't working right.
Maybe it drips too, as a result, who knows, but my net results is sometimes it leaves the fuel line bone dry when you're turning the bike over and over forever.
Thanks Cody! I appreciate the info on that.. I'm going to order a new one.
09 vtx1300. Used my brake bleeder vac pump and diaphram would not hold vacuum..! Thanks for varifying it for me...!
Had the "sticking" problem on a Suzuki GS500 due to contaminated fuel (due to corrosion in the tank) which I had no idea what was going on ; I now know exactly what happened back then ! Thx
Thank you for the video! I have a cb650 SC 1984 nighthawk. I took the airbox out and put some carb air pod filters on them. I can't get my bike to fire. It spits and tried but my buddy told me I need to get my carburetor with bigger ports to allow more gas into the carbs.
Do you know what he is talking about and do you have any content highlighting this issue?
Hi great video I've just replaced both diaphragms and spring on my 1983 GL650 yet fuel is still pouring out of the petrol tap when the engine isn't running.
Thank you for your video, very informative. I have a 1972 that uses vacuum fuel valve, can a vacuum leak also cause number 2 cylinder to leak fuel out of the Overflow after engine shuts off?
Thanks for this video. I have a 1981 Honda CB900c with a automatic fuel valve. It's been bipassed because the parts are unavailable. Is it worth finding a repair kit for it and do you know where I can find one?
Great video, brother! Had a problem like that and changed for a new pump. However after changing the engine oil it still smelled of gas. Is that normal?
I'll be sure to check mine tomorrow when I balance the carbs!
Checked it out today, I guess that makes me a sucker... Works fine though, no gas chuggage! Thanks very much for the tip.
Well there’s another part to add to the list at the next service. My Shadow runs great, but I was testing this by applying vacuum as you describe, and it doesn’t hold vacuum. I have to wonder if that small vacuum leak would cause some intermittent anomalies on the bike. At least you can buy just the vacuum diaphragm piece!
So this valve started leaking last week, and I have a new OEM one sitting at home waiting to go in 👍
My CB600f Hornet has a big blob of clay or similar inside the fuel valve blocking the vacuum pipe. I guess that the diaphragm tore and somebody decided to do some serious bodge job on it! Bike did run fine for a few hundred miles after I bought it, however then it started running on three, breaking down etc. So I'm fixing it up to run again. The more I take it apart the more bodges I'll find I bet!
You’re not alone man! Good find 👍🏻
Really nice on how you had explained how it works and how to test a Woking vacuum operated valve. Thanks and keep up the great work.
Geez, it's nearly 4 years ago, I hope you can see this comment. Firstly I speak in metric but I think you'll get the gist...I have a case where the fuel stops getting to the carb when the tank gets low. My cruiser, a GV250, has a 14L tank. I should be doing around 350 to 400kms but by 190 to 230 kms, it could start to cut out. Spluttering, backfiring, the works therefore when that happens or just before it does, I have to switch to the reserve tank. Yesterday just to check and after having to switch to the reserve, I emptied the fuel out to see how much I had left and found that I had at least 3.5L left which should take me for another 100 kms I think.
I have taken it to the mechanics and after $$$, they can't find anything wrong. Myself I have emptied the tank and removed to clean and see, and also the fuel valve..and nothing, mind you I'm no mechanic. After 2-3 years with this problem, I think I may have found the problem and it may happen that the pressure of a full tank allows the fuel to the carb, VIA a Vacuum fuel pump, seamlessly, until the pressure gets low and then I have this problem. Would I be right to think this? Anyway thanks for the video.
Replacing my 90's Suzuki DR125 Pet cock because of leaking. Found an extra tube going back to the carb ! !~ So, looks like I have a vacuum fuel valve (WHO WOULD KNOW !). Anyway, will dig into it and see if I can find a problem with the Vacuum fuel shutoff. Would be nice to not have to buy an entire new Pet Cock assembly. Thanks for the nice easy to understand video !
Thanks brother. U helped me figure out my issue on my 2003 Suzuki Volusia. Keep the helpful hints and keep education coming.
Awesome video..I have a 1996 Honda 750 Magna..Is it necessary to suck on the vacuum hose to allow the carb float bowls to fill with gas before the engine is running? I replaced both the on off petcock and the auto valve..I opened the drain plug on each carb and got mostly gas stabilizer. The bike just doesnt seem to be getting gas to the carb..The spark plugs are dry if you know what I mean..Thanks..hope all is well..
Great info. I wish this would help me solve my issue, but at least i learned a few thingsd... My Yamaha only runs on "reserve" (the reserve is a button on handlebars, the petcock itself only has "on" and "off", there is not "prime" either). Only thing I did was replace the o-rings and my petcock doesnt leak now (the reason why i took it apart), but now the bike only runs with the switch on "reserve". Any suggestion what I did wrong?
wow amazing and educational video much appreciated it helped me alot. I have a question Where can I find diaphragm for 1982 Honda CB900 Custom ? is it oem part or can it be purchased online after market ? Thank you again.
Just watched video great information ,but needed info on a vacuum fuel valve leaking out of its bottom over flow tube? which was briefly mentioned. Does this mean it is stuck open?
Perfect ! TY!!
Just had the peacock flow problem on my sun atv and solved after watching your great video diy/how to!
Great vid. I'm having a few running issues on my 82 Gsx400f and this will now be added to the list of things to check. Cheers.
+olrenison I hope this sheds some light on some problems brother!
Dude I have been stumped on why my bike is running like shit (it’s a 89 transalp ) I think you just helped me figure it out. The cylinder it pulls vaccum from keeps fouling out and running like shit , I’m going to run it off of a gravity fuel bottle and see
hey friend fuel valves that you demonstrate is same with the fuel valves that i have for my cb400, but every time i turn on the bike there's a fuel leaking in the tiny whole that you mention in your video. is sign of bad valves.? or it's normal.
thank you
Great video, thanks for explaining. I recently noticed fuel smell in the engine oil of my Honda so I guess my valve is shot, too.
Hi, Thank you for this helpful video. I have a 50CC scooter that uses a vaccuum valve and as it was not starting and no fuel seemed to be flowing from the tank I suspected it was the valve, I did your suck test on it and it is not pulling any vaccuum at all. So thanks for the helpful video.
Thank you that is exactly the kind of problem that i have
Cheers for the information .
Thanks Cody. Very informative. My 86 Honda scooter intermittently bogs like it isn't getting enough gas. I've cleaned the carbs twice but still have the problem. I sucked on the vacuum line and fuel dribbles out of the petcock. It seems like low flow. I may have a torn diaphragm. My petcock is probably 33 years old. I will investigate further. What do you think about a cheap Chinese petcock replacement?
I never even heard of a vacuum fuel petcock until mine quit working. It's a bad design, i am going to replace it with a normal on-off-reserve valve. Whats the point of vacuum fuel valve anyway? Just so you don't forget to turn off the gas?
Great video! What about. Fuel reserve on petcock not working just bought a 1982 cb900f runs super strong. Bike started chugging so I flipped it to reserve bike stalled. Pulled over still had half gallon or so in tank. Put 2 gallons in started right up!! Think valve is bad or just the reserve filter clogged????
Great video man, sure did learn alot.. I have a 1996 Vulcan 800.. it's also a vacuum petcock, and I get gas coming out the exhaust when it sits for a while. After watching your video I checked and found that my Petcock flows gas when set to ON, AND RESERVE.. (WITH THE ENGINE TURNED OFF)...what do you think about that?? Any information from you, or anyone out there would greatly appreciate..