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

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.

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.

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.

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!

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

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!

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.

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

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.

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

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! 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!

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

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.

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

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

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

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!

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. .

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

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!

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

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.

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 !!!

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

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

Just had the peacock flow problem on my sun atv and solved after watching your great video diy/how to!

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

Thanks for sharing , i was scratchin my head last night cause i couldnt figure out why i wasnt getting fuel on my kitanna , never even knew they had vacuum powered valve

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

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.

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.

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!

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

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.

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 🙏

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, thanks for explaining. I recently noticed fuel smell in the engine oil of my Honda so I guess my valve is shot, too.

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 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.

Thank you man, this is the prob, i had on my cbr900rr sc33, now its done thanks to you

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.

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

Awesome information Cody, Happy 4th of July Dude.... Ride on !

Best motorcycle mechanic on the internet!

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

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

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.

I'll be sure to check mine tomorrow when I balance the carbs!

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

Having problems with my 1992 Nighthawk. This video was very helpful'

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

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

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.

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!

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

Thank you for answering all my questions you're awesome dude Related to the fuel regulator

Thank you! this is a new learning I did not knew this exist!

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.

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!

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. 👍👍

U the man very helpful my guy thank you for taking ur lil time to make this video

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.

Thank you that is exactly the kind of problem that i have

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”.

This aged well. Yeah this is a forever video. Well done Sir

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.

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

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 !

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!

Thanks bro, I will check it out on my 750ACE. Excellent video, I believe that you know your stuff. I like how you explain the different scenarios of possible 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.

Thks four your excellent video I have a Peugeot v clic is start today spilling gasoline through the tank breather whitch reason thank you so much

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

bout to be on my magna soon thanks to your info thanks

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 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...

great video mate. very informative thanks for sharing.

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!

Thank you very much, this video saved me several headaches, really great job explaining all this.

Well spoken, easy to understand its clear and simple information

Perfect advice "JUST RIDE YOUR BIKE!!!!!"

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.

NIce one, mate, very informative and clear. I have a VF500 and your video has given me the information I need to hopefully diagnose my fuel supply problems. Cheers!

A 2000 Suzuki sv650 brought me here. 😂. Great video🎉🎉

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.

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

awesome dude u make mechanics of all of us.... u hit my problem square on the head with this video shout out 2 u and thanks from south africa cape town.

Kodi great info I sent your video to my son who is having this problem thank's mate

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.

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.

Yep sounds like my issue stuck floats, as fuel coming out overflow when trying to run ,Cheers matey

Hi mate, kawasaki volcan500 oldschool early 90 ies...my carbs floated until my airfilter was bathing in 2 inch fuel! ...i have manuel vacuumpump, i try the test, i check, appreciation from Belgium Europe dude!🇧🇪🍺👌, motor stood for 10 years...carbs rebuilt compleet is way to go i guess😎

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?

I love you man.. I finally was able to solve my bike problem

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?