For OF and Routy...I had petcock problems once. Bike was stumbling, dying, and flooding the carb. First I replaced the needle and seat. I had to go back in and recheck it as it was still flooding. Once I fixed that problem, I did Serowbots test and determined it was, indeed, the petcock that was at fault. I got the rebuild kit and installed it. Bike did the exact same thing. Yes, I replaced the vacuum lines too. I didn't have the $ for a Raptor at the time, so what I did is I removed the vacuum line altogether, plugged the carb end and the petcock end of vacuum line connection, and I put it on prime. I have been happily (almost) riding this way ever since. No flooding, no stumbling, no dying. And I don't shut it "off" when parked. (so I know the needle and seat are working properly) I may get a Raptor someday, if I have the bike long enough.

Troubleshooting them durn vac petcocks sure can get confusin' .....

You works on them and works on them and they still let you down in some new way that you thought you had stopped.

Poor Routy -- tell the nice Drums1 man how to test analyze and fix his design & materials flaw free vac petcock, Routy.  

Succeed without a total kit rebuild and I'll eat my bite of musty crow meat and spit out the rest of the mouthful of greasy black feathers ....



He's willing to work with you -- man, what an opportunity !!



Once you admit your total defeat however, then it is the Raptor Party's turn at bat.

And if we succeed where you failed, guess what you get to eat?


                     fair is fair after all ..... he'd insist that I eat it

OF, I did do the total rebuild kit on the vacuum petcork. With new vacuum line, petcock rebuilt, new needle and seat, and fresh gas, it still ran like yak poo until I put it on prime and eliminated the vac hose. (plugging both ends, of course) It made no sense to me at the time, but it's basically running the OE petcock as if it were a Raptor. It works, at least for now.

I thought the Raptor had no reserve? (on-off) I haven't run out of gas yet running it this way. I check that before every ride. And I never go far enough to use the whole tank, since I bashed the motor in. I don't miss having reserve, I just remain aware that I don't have it.

Does anyone know what a suitable replacement would be for the current mikuni carb?

Iono wrote on 08/25/11 at 16:44:50:

These have a vacuum actuated decel valve (it gives a squirt at high vacuum during decel to ease backfires)...
... an accelerator pump is usually mechanical, and gives a squirt when you gas it... (for less hesitation at launch)...

Almost opposites... ...

Iono wrote on 08/24/11 at 16:17:09:


VM38 is a likely candidate.  You'll need a new cable though.