On multiple occasions now I've had my Raptor fail and start leaking fuel from the face.  It only happens after moving the selector, and seems to be remedied by moving it again back and forth.  When it leaks, it drips approximately 1 drop/sec.  Sometimes the selector sticks and is difficult to move, but a bit of turning free it up.  The difficult moving and leaking face don't always coincide with each other, though.

Has anyone else had this?  I'm going to start looking into rebuilding my petcock, or at least disassembling it to see if my seal is damaged or something else is going on.

EDIT:  Part of my issue is that it's a confirmed Yami petcock that was new in the package when I installed it 14 months ago.

Ethanol. Perfectly normal. It's considered routine maintenance these days (after several petcock recalls in the late 90s and early 00s for the same reason, Honda, Suzuki, Kawasaki, Yamaha, Harley Davidson, a few others)...  

Ethanol proof seals cost an extra 25 cents to make.

I bought my bike with a bad pet.... so, I've had a Raptor 7yrs...  using EPA, unleaded, MTBE, 10% ethanol fuel... and it's still fine...
1yr failure is a fluke... (maybe a bad 0-ring gasket from the factory)...

At $15-20, yeah a rebuild kit is a complete ripoff.  I was also thinking about disassembling the petcock last night.  Here is the rebuild of a very similar Yamaha petcock:



The silver lining to all of this is that I don't always let the bike run down to the reserve, and so long as I don't turn the lever I don't really risk it leaking.  I'll be taking the bike to work today, but either tonight or tomorrow I'll disassemble the petcock.  It's supposed to rain Thursday and Friday, anyways.  When I do, I'll take plenty of pictures.

Is the O-ring REALLY supposed to be greased from the factory?  I would think that would contaminate your fuel, and that gas would provide lubricating properties for this O-ring.  Of course, what's true with pure gasoline isn't always true with 10% ethanol.

If my problem is simply a nicked/damaged O-ring, I might ask Yami for a new one.  However, to cut down on wait time I might go to my local autozone and look for the closest I can get for whatever spare change is in my pocket.  Of course, is my :0 shaped seal is damaged, it'll need an actual Yami kit.

Is a lubed O-ring necessary... I don't know for sure.

I always put a very light coating of silicone grease on them whenever I install an o-ring.  Enough to offer a slicky surface - but not enough to allow greasy globs to wash off.  I put a little coating of lube on my fingers and then just rub the 0-ring between my fingers until it is shiny.

Ok everybody, HERE IT COMES.  These are the two most important things in any forum: pictures and answers, but first I must elaborate.  APPARENTLY I remember things that never happened.  Not the fuel leak, that was real...  I think...    However, it would seem that I didn't buy a verified Yamaha part, but the cheapo Chinese knock-off.  This explains why my 5/16" line never fit right on the petcock, and why I had to switch to 1/4".  When I did this I also did a flow test, and it passed well.  Often times in the "OFF" position to remove the carburetor, there would still be a very slow, creeping drip.  I suppose this (might) explain that too.  With all of this in mind - mainly that this is NOT P/N 5LP-24500-01-00 - we shall continue.

This is everything within my petcock.  Left to right, you have the main body, seal, faceplate screws, faceplate, wave washer, and valve lever.



Here is the backside of the valve lever.  This pathway connects one of the two top holes to the bottom hole OR it can also connect the two top holes to each other in the "OFF" position.  This piece is nice and smooth.



This is my seal.  What I'm pointing to is  a small nick in the sealing surface to the bottom hole going to the fuel outlet.  While this won't matter in the "OFF" position, it could certainly cause a leak when "ON."



My main valve body.  On the left side in front of the brass stem, there would be "H14" stamped there if it was a Yamaha part.  That and the two knobs on the outlet were the signs leading me to realize my mistake.  Inside the rotary portion of the body towards the bottom, I found a small bur or poor casting.  I suppose it was more like a flake.  It was generally flat with the metal, but was able to rise up.  It seemed to run front to back as the picture faces.  I removed it and smoothed it out before the picture was taken.  The rest of the cast also seems rough.  I'm not sure if that is a quality unique to the Chinese knock off, or if that will be common.

He does look happy...  ...

Why lube the rubber parts on all sides with grease?

If the thing is working correctly and sealing off the gasoline like it should, then there are surfaces that will never see gasoline.  These surfaces (and the mating metal parts) will never be wetted with anything.  So they need a permanent style "sliding lube" like a grease so they can slide easily for as long as possible.

Associated fact about rubber -- it has oil and wax as part of its construction and when rubber finally "dries out" and stiffens it has lost most of its oil component.   By supplying the other side of the part with a grease reservoir, the rubber components will last longer before becoming stiff and not working well any more.

By greasing it up good you make it work better and last longer.


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HondaLavis, you might want to retitle your thread to say "Chinese Petcock Failure" that way the search engine won't be plunking this thing up on Raptor searches every time the newbies go to looking for Raptor stuff.

It warn't a Raptor after all.