Fuel Petcock Fuel Tap STUDY How do they work? Kawasaki Ninja Yamaha Virago

Fuel Petcock Fuel Tap STUDY How do they work? Kawasaki Ninja Yamaha Virago

[@MatthewJFitzpatrick]

The Prime function is for vacuum-controlled petcocks. Normally fuel only flows when there vacuum (ie. engine running). For cold starts you would turn it to prime to allow fuel to flow (gravity-fed) freely to prime the carbs (and then you would then of course turn the choke on). Once the bike initially starts, then you'd switch the petcock to ON position.

[@nimeshasangamunasinghe4808]

How to turn off the fuel tap ? There is only prime, Res and on only my left side carburetor is overflowing when i stop the bike . Yamaha xs 250 2003

[@fitzstermoto]

@@nimeshasangamunasinghe4808 When the bike is NOT running, it should be left in the ON position. Like I mentioned previously, fuel would typically only flow in the ON position while the engine is running due to the vacuum pressure sucking the fuel. If fuel is still flowing on your bike in the ON position, even when the engine is not running, then your petcock is most likely bad and needs to be rebuilt or replaced. Most vacuum-controlled petcocks have some type of rubber diaphragm inside to manipulate the vacuum pressure. If that diaphragm is cracked or dried out/old, then it can't maintain vacuum pressure any longer and as a result, fuel will constantly flow in any position. If you have a good factory or service manual for your bike, it should hopefully have a breakdown and explanation of the petcock and further explain how it functions in your specific bike. I hope this helps - good luck! Edit - Just thought of one other thing that could cause that same issue (if not the diaphragm), and it could also be if you have any contamination in your fuel tank (rust, dirt, etc) - it's possible for something to get through the filter and get stuck or jammed inside of the petcock, which would then prevent it from sealing properly after the engine is stopped. This would be a much less common scenario but it is possible and have seen it before (however not likely).

[@nimeshasangamunasinghe4808]

@@fitzstermoto Thank you so much. Very helpful information thank you very much sir

[@nimeshasangamunasinghe4808]

@@fitzstermoto sir.. What is the recommend idle speed for yamaha xs250 special

[@emmettturner9452]

Every OEM Kawasaki EX250J petcock I’ve seen leaks. Of course, I only realize this after I buy a brand new one to replace my leaky one only to come back to the bike after years in storage to find that the entire tank of Ethanol Free fuel drained out of the tank, through the carbs, and into the crank. RUINED everything.

[@lerp85]

Any chance you have that virago 500 petcock still? I am looking for one.

[@mcycleshawn]

As you may already know......those are a hot commodity. Already sold and shipped! If I find another I’ll let you know!

[@audiofella5066]

The taller one looks like it is for a ninja 250r / 250f i'm pretty sure because i've been looking for one actually, and they need to be tall like that to clear the tank on the 250r, all the cheap Chinese ones don't even clear the tank for access to the switch, the bike i just bought has a cheap Chinese one that has been modified and put in reverse and filed / ground down to fit LOL. The dealer wants $125 for an OEM one!!!!

[@20Remy11]

how can i replace those tiny filters? any suggestions…?

[@mcycleshawn]

They lift out but should be a tight fit.

[@20Remy11]

@@mcycleshawn they fell out and were pretty rusty. i nee replacement, thats what i meant

[@mcycleshawn]

@@20Remy11 it is very hard to find replacement filters for our older bikes. Sometimes they sell rebuild kits on eBay but often do not come with filters. If you can clean them and reuse it’s the best or find another working oem one in tact. Otherwise aftermarket are the way to go but there is a lot of junk out there

[@h.l.a.chuckie8709]

Got mine soaking in gas now.right on time

[@davidwinkle9652]

250 ninja