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Fuel drip on petcock
- Thread starter RVA804
- Start date
When the diaphragm starts leaking on the vacuum petcocks it will fill the backside, run down the vacuum line to the intake tract of the head. There is a chance it could run on into the case diluting your oil. Yamaha designed a channel in the spacer plate to let you know this was happening but with time they become clogged with road grime and varnish. You might check to see if this is the case.
On any gasoline engine, car/truck/bike/marine engine/aircraft engine, you want zero fuel leakage. No tolerance for even small leaks.
The ones you have are worn out. Buy a new manual petcock(s).
The ones you have are worn out. Buy a new manual petcock(s).
RVA804
XS650 Enthusiast
Do you have any recommendations on which to buy? Also, I remove the fuel line and there is no leakage when in "on" and "reserve" position. But, when I switch from on to reserve there is a small drip but only when switching to reserve.
I hate to recommend Mikesxs, because many of their parts are poor quality. However, I have been using the Mikesxs.com manual petcocks for about 9 years now, and they are still working very well.
They have gone up in price, expensive now. You only need one petcock, even if your tank has 2 openings.
They have gone up in price, expensive now. You only need one petcock, even if your tank has 2 openings.
RVA804
XS650 Enthusiast
Great, thank you. It appears to be a rather easy swap with the vacuum one in there now... am I correct? Sorry, I am very new at this... I very much appreciate the help!
Yes it is an e z swap. But part #17 is a lot cheaper. IF that is the problem.
RVA804
XS650 Enthusiast
I have been watching videos on youtube... it's all starting to come together! This forum has been a great resource, great to have this place and I hope to someday be able to help others.
Hi RVA804.
while it's possible to dig into your previous posts to find that your bike is an '81 Bobber, it'd be helpful if you built that information into your signature line.
It's easy. Even I can do it. See mine below.
OK then, '81 XS650s came with a single vacuum-operated fuel petcock. MikesXS sells a manual fuel petcock that'll fit in it's place. Or you can rebuild your petcock to eliminate the vacuum operation system but you are still left with 35 year old rubber parts if you do.
while it's possible to dig into your previous posts to find that your bike is an '81 Bobber, it'd be helpful if you built that information into your signature line.
It's easy. Even I can do it. See mine below.
OK then, '81 XS650s came with a single vacuum-operated fuel petcock. MikesXS sells a manual fuel petcock that'll fit in it's place. Or you can rebuild your petcock to eliminate the vacuum operation system but you are still left with 35 year old rubber parts if you do.
RVA804
XS650 Enthusiast
Done
I ignored this slight leak for awhile and suddenly it started pouring. I had gasket paper and a sharp pocket knife. I had to empty the tank to fix it and I emptied it into the tank of an ATV a guy had there and then I did this real quick and got gas some gas back from him. When I go to town I bought the valve and crimped the hose with a vice grip while I put the valve in. My part #17 was still good. If it isn't, there are things you can try, like turning it over.
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