Help with 82 kz250

1977-Z1-A1-LTD wrote: You may have tried this since I'm late to the party, but it sounds like a carb issue to me, and in fact un-metered fuel being dumped directly into the cylinder. If you're fouling the plug, you should also be seeing black smoke from the exhaust. Does the bowl vent have any fuel in it? If so, you may need to try "lapping" the float needle to make sure it has a really good seat, be sure the floats are not touching the top of the float bowl when you push down on the float/needle when the carb is upside down. Another check is a "pop-off" test, with the carb upside down and the floats and needle in place, put a bit of soapy water around the float needle and blow some air into the fuel intake port on the carb (less than 10 psi). If you see bubbles the float needle is leaking. I feel your pain, went through the exact same thing on 4 carbs..

missionkz wrote: Yes low compression means incomplete combustion and rich mixture symptoms.
I would think a used engine should be compressing more like 135-150 psi range.

swest wrote: Did you check your cam timing?
Steve

pete greek1 wrote: When you did the compression check did you have it WOT ?
Pete

82 kz250l wrote:

swest wrote: Did you check your cam timing?
Steve

Yes I advanced it an retard it...an there was no change to the way it was runing

1977-Z1-A1-LTD wrote: I went back through previous posts, and I know you indicated checking the cam timing, but what you're describing with low compression and an accumulation of un-ignited fuel in the cylinder could be a sticking (or bent) valve or the push rod is bent and not opening the valve, etc. Did you also check valve clearances?

swest wrote:

82 kz250l wrote:

swest wrote: Did you check your cam timing?
Steve

Yes I advanced it an retard it...an there was no change to the way it was runing

I didn't mean your ignition timing. If you advance or retard the cam timing you run the risk of bent valves.
Steve

swest wrote: Fill the ports with gas or some kind of solvent and see if the valves leak. It doesn't take much. Low miles, the rings should be still good.
Steve