Petcock flowing fuel when off

[randy]

I've been struggling with a wacky petcock for months now. The left one flows fuel with no vacuum applied. After taking it apart numerous times, double checking the assembly, stretching the spring, yada , yada, I finally got another pair on ebay to use for parts. While I was at it, I ordered a rebuild kit as well. Mind you now, the petcocks were rebuilt last year, but I don't like to take any chances. When in doubt, replace it, that's my motto.

I can now strip and re-assemble my petcocks blindfolded quicker than my M-16.

I found something very interesting. The plunger (the thing that cuts off the fuel) in the K&L rebuild kit is SHORTER than the original plunger. It's only off by a gnat's ass, but it's enough to flow a lot of fuel.

What a ****ing disgrace.


I installed the longer one from the used petcock and viola!

[Ken Talbot]

I hear you, Randy. This is sort of like K&L's version of jet numbers. I've lost track of how many people have bought new jets just one or two sizes larger than stock (because they've gone to indy filters and/or 4-1 exhaust), only to find the K&L numbering system bears no resemblance to Mikuni's. I've seen this problem with K&L petcock rebuild kits before too, but it still catches people unawares. .

[randy]

Hey, Ken,

The worst insult is that I rebuilt both petcocks at the same time during my resto and the right one NEVER leaked. Go figure.

[Dragonrider]

Same for the octopus rebuild part from K&N...it's wrong and will not close the valve.

I wrote them about it, but never got a reply.

[Winterhawk]

Using K+L,s petcock reuild kits I've had good luck thinning out the recessed part in the plastic block. This allows the plunger to move closer to its seat.