How To Test A Vacuum Operated Fuel Valve

[@matblackgraviton]

Dude- people like you are making the internet great again! Thanks for sharing your knowledge out to us plebes.

[@rikherlaar]

Couldn't agree more ;-)

[@clivecarrington8814]

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.

[@antoniomoreno928]

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...

[@scoutydoggers6998]

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!

[@cars2514]

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

[@NorthJorgie89]

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.

[@TheMotorcycleMD]

+NorthJorgie89 That's awesome man! No problem!

[@isaacaskey1410]

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!

[@brentmcgillis]

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 KZbin video, I hope to solve the mystery that has stumped bike shops for 5 years now.

[@fatboyfollies4188]

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.

[@Hendrix.]

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.

[@michaelanderson3771]

So helpful Cody - I did not know this vacuum valve could cause so many issues. Great video Sir.

[@guitarforlife238]

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

[@4984Snake]

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

[@jasonburks8010]

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!

[@luckyk1751]

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 !!!

[@Springercycles]

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.

[@appmia1]

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. .

[@docsooter1]

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.

[@gkup]

What is a pallet screw? And how do you adjust it. Thanks for your help.

[@NBMedia8928]

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.

[@macmorgan6685]

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!

[@stevepodesta1906]

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!

[@Turbofab]

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

[@TheMotorcycleMD]

Hope it fixes the issue brother!

[@Turbofab]

@@TheMotorcycleMD I can confirm the issue was the tap so I appreciate your video and the further aggro it saved me

[@MotoMango]

Best motorcycle mechanic on the internet!

[@markrdixon1]

Great video, Cody! Well explained, extremely informative. Thank you for taking the time to educate.

[@SteveRingwood]

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!

[@risanch]

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

[@TheThomasmcneil]

I googled fuel issues for my older harley sportster and this video came up. Very informative, thank you.

[@NickellBag227]

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

[@ratchbrg3882]

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

[@choppergirl]

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.

[@JNPhere]

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.

[@richarmarsh8739]

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.

[@wtimber]

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.

[@Megaharam]

Hey dude thanks for the info, I have a 1994 CB500 with the same issues. Thanks to you I know what to do. Awesome.

[@ginapower8149]

Great video. Have have no end of trouble sorting out a fuel drowning problem until I came across your footage. Thank you.

[@Spacerider1]

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.

[@kaput450]

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!

[@buddruffin]

Great information, very helpful. It helped me to get my bike running perfectly. I did not imagine that that was the problem.

[@dannysmits9706]

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.

[@chuckiewaller5431]

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

[@fkat28]

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?

[@santiagobecthold8544]

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

[@kevinmorgeson650]

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!

[@stevegraessle854]

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?

[@IrudayarajAlwin]

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.

[@markwhiter8908]

Thanks for sharing your knowledge. I’ve had this issue before and never really understood how the whole vac. Thing worked. Thanks again !

[@colingordon4]

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 🇬🇧👍🇬🇧👍🇬🇧

[@TheMotorcycleMD]

👌🏻👌🏻

[@shazbotnanunanu4980]

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.

[@TheMotorcycleMD]

+Paul Sterling The best advice you can ever give someone 🤙🤙

[@billleskeep2033]

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.

[@xzouix]

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?

[@etarepsedllits48]

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.

[@MrNoobMaster96]

This dude made the perfect video where he showed the inside of the vacuum diaphragm, i mean how it works!!!

[@gregleonard7391]

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

[@brianj1204]

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.

[@Stormy956]

This was great and EXACTLY what I've been dealing with on my 2005 Shadow! Thank you for the information!!!

[@hoondaily270]

Aero?

[@בןאדר-ט9פ]

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 🙏

[@inajefflymanner]

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.

[@CristianDiaz-tg1pj]

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?

[@richardedwards2463]

Can I ask you a question? My Valkyrie reserve does not work or rather when I shift it to "reserve" I am out of gas. What should I fix? Rebuild the petcock? Thank you.

[@mikegarrett861]

09 vtx1300. Used my brake bleeder vac pump and diaphram would not hold vacuum..! Thanks for varifying it for me...!

[@royholden9035]

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

[@puskrat]

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.

[@TheMotorcycleMD]

+Jeff Puskarich Knowledge is power! (and a money saver) 🤙

[@rosemariehauschild3064]

Jeff Puskarich I

[@user-sk9sl2qw8v]

i have a question, should the vacuum hose be moving air freely if its not connected to either the petcock or the othere side?

[@harpham69]

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...

[@russlogan9130]

Thanks Cody! I appreciate the info on that.. I'm going to order a new one.

[@jeffyhuey]

Ah, so that's where the stain is coming from. Ok, 2004 vtx 1300. Found water in large vacuum tube going to air box. What is the function of those two big hoses coming from the top of the cylinders? Is that part of the vacuum system for gas flow?

[@jimmyvalenzuela5050]

Thanks brother. U helped me figure out my issue on my 2003 Suzuki Volusia. Keep the helpful hints and keep education coming.

[@robbyhudgens3170]

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.

[@lukemazur5251]

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.

[@aaronm8046]

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?

[@kendtchileninjah5905]

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

[@randyfrancis5940]

Where does the pitcock vacuum line hook up to on a1985 honda shadow vt 500

[@jamesbrackjr764]

My 2000 Suzuki quadrunner 500 4×4 had a vacuum pitcock on it but I replaced it with a basic on and ran great about few months then now it over flows out the overflow tube and it will crank but when I hit the throttle it won't go and spits and sputters

[@olrenison]

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.

[@TheMotorcycleMD]

+olrenison I hope this sheds some light on some problems brother!

[@charlie_sin_mag]

Could you bypass the diaphragm all together (remove it), put an o ring in its place to stop any leaks and just have the fuel free flowing?

[@CarlosGlatzos976]

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.

[@arlenejnelson]

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?

[@omitted_hornet8641]

Is it possible to swap a gravity fed / vacuum fed fuel system for one with a pump??

[@markjones4572]

Hi, thanks for the tutorial. I live in England. I have a Kawasaki H2 KH750 . It has 3 fuel lines and a prime on a vacuum tap. No fuel is getting to the cylinders after full engine rebuild and carb clean. I noticed that the spring is missing behind the diaphragm. I can get fuel to flow from the 3 main pipes on prime, but not on or reserve and the bike won't start. Is the missing spring causing this.

[@boedacres]

Thanks for the Info. I have a atv quad master that the air box was full of old nasty gas. after cleaning it out the bike did start but no idle and major full rich found the vacuum line sucking fuel

[@davechristoffersen1690]

Dude, @1:22, is that big bad Bobs' badly bent and barely broken used bies?

[@1vincej1]

I own a 2003 750 nighthawk. It has 3,900 miles on it. My fuel tank petcock only has the short pipe on it. It doesn't have the strainer and o ring. I see on some of those short pipes. There is a o ring or black tube on the end of that pipe. Does that have to be there? I ordered the "kit" from Honda. And what holds the o ring on that goes on the strainer? Thanx for your help

[@Jackson.verte01]

Hey I'm not sure if you'll see this but I have a 2006 Honda vtr250 which is vacuum operated. When the bike is running fuel drips from the nipple that you briefly addressed, the face of my peacock is also brown. The bike runs fine but it slowly drips fuel. Any insight would be great, thanks.

[@TheMotorcycleMD]

That’s easy! Replace the diaphragm bro!!

[@Jackson.verte01]

@@TheMotorcycleMD okay sweet thankyou!

[@kopincouplekoreanaandpinoy4917]

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

[@VideoByPatrick]

Thanks for posting, great info. I was confused early on in your demos of vac. operations as seems Vac has to be constant/strong for good fuel flow versus weak and leaking AIR.

[@trupacabra]

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?

[@rayworx]

just saw your post and noticed my old orange CB750 in the background! Well... it's not actually mine but I had one just like it. Hummmm a mouth full of gas? Maybe a good reason to use a vacuum pump instead?

[@TheMotorcycleMD]

Well that’s no fun!

[@EvendimataE]

do all honda valves have the same thread size.....im wondering if the shadow aero valve would fit the magna?

[@antonyhoch]

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.

[@jaycarter796]

Thanks, excellent video and very informative. I'm beginning to wonder now if this is the issue with my XF650...one way to find out!

[@BigDaddy-nt2xc]

I have a 1999 Heritage Softail Classic, my petcock has a vacuum hose connected to the rear. I wanted to try a high-flow petcock without using the vacuum hose. Can this be done? And what do you do with the vacuum hose? I have a stage 2 Harley. Thanks brother

[@kennethkrajewski9443]

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????

[@shanemyers4142]

Mine idles great. But Is it possible the vacume pump could be bad if it dies upon throttle? It only revs normal wen I spray fuel in carbs while it's idling.

[@Motivated-94]

I going to be leaving for whole year i just bought CBR 600 F2 should i be worried about gas valve being stuck since it runs on gravity feed.

[@curliecardenas]

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..

[@georgescrivner7305]

Just replaced my petcock, no gas flow! Vacuum operated? Smaller hose going to carb? (Duh!!! on me). Thanks for the info.

[@kizito8301]

I took out the carburettor from a 1980 cb750 for cleaning, and when I tried to put it back on the motorcycle, I was able to connect the fuel line back to the gas tank but could not find where the other smaller line goes. All I can see is that it looks like it should be going somewhere around the airbox but cannot seem to find where it plugs in. I have check the manuals and can find any reference to where this second line goes. Please you would be my superhero if you can help me figure this out?

[@melanie-annethibeau2087]

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

[@VirantRoss]

*I have a Yerfdog Rover UTV w/ a GY6 and it appears to have similar diagram on top the tank. So I can just suck on it to test it?? My fuel filter is dry out of nowhere*