Drip, drip, drip

I rebuilt the vacuum petcock on my '82 Maxim. Did careful job and even put a thin washer behind the diaphragm spring for a little more pressure on the shut off plunger. After a couple of weeks I noticed that the starter would occasionally spin and/or it was hard to start. Long story short the petcock still drips an ounce or so every few days. Sure enough, even though it did not smell like gas, my oil level was higher than I remembered it. Looks like an oil change and a manual petcock should solve both problems. I am sure this story has been repeated many times in these pages.

 

Did you polish the petcock body?
It's actually quite uncommon (but not unheard of) for a vacuum petcock to be faulty after a rebuild.

Rebuilding the Yamaha Vacuum Fuel Valve w/pics

 

With a polish and rebuild kit from xj4ever my petcock is flawless.

 

Well, I may have to try polishing the body. I built up a XS400 (see pic) last year and redid its petcock. Works great, but the one on this XJ was leaking when I got and still is. Might have to inspect the body more carefully. Maybe there is some flaw that I missed.

 

if your oil level is rising you have more than a petcock problem unless the pet cock is leaking fuel back into the motor via the vacuum line. float needle valves would cause fuel to flow into motor when sitting

 

That is a slick little xs! You should start a thread about it.

 

Good point. I did put in new float valves and checked levels via the "clear tube" method but may have to check again. I do have a clear vacuum line and not seeing anything there.

 

Thanks, I may do that. It was one of four of my bikes featured on the August Dime City Cycles blog. I shortened the seat pan by 4" and the rear fender by 5". The seat still swings up like original.