Help with 82 kz250

swest wrote: Piston, bore, valves, bike.
Steve

Here's the bike I'll get the rest tomorow

82 kz250l wrote: In my experience any ring gap past.017 is JUNK. That's when I noticed lots of blow bye out of the crank case, fuel in the crank case and started to use oil....this is my opinion

Well, I think you are wrong. .017" gap isn't junk and neither is .027". Large? Yes. But be the cause all these consternations? I just don't think so.
I have a feeling it is something else, like the rings simply did not seat or wear in correctly.

That gap by itself is not going to cause the problems described. Is that gap the result of worn rings? Maybe, but I don't see how anyone would know that answer without seeing the rings unless they knew what the gap was set to when the rings were new; it may have already been set wide. Ed

Does a 250 have a overhead cam - cam chain?

Whatever is opening valves needs to be set at TDC, otherwise the ignition timing will never be in sync. Sorry but I don't know much about the 250's but think you need to understand the comments about "cam timing".

:huh: < :dry: >> < :woohoo: !

:huh:
Steve

missionkz wrote:

82 kz250l wrote: In my experience any ring gap past.017 is JUNK. That's when I noticed lots of blow bye out of the crank case, fuel in the crank case and started to use oil....this is my opinion

Well, I think you are wrong. .017" gap isn't junk and neither is .027". Large? Yes. But be the cause all these consternations? I just don't think so.
I have a feeling it is something else, like the rings simply did not seat or wear in correctly.

What do you think could be the problem the rings?

LineArtist wrote: Does a 250 have a overhead cam - cam chain?

Whatever is opening valves needs to be set at TDC, otherwise the ignition timing will never be in sync. Sorry but I don't know much about the 250's but think you need to understand the comments about "cam timing".

:huh: < :dry: >> < :woohoo: !

Yes it does....I do understand cam timing....only reason I adjusted it was to get the bike to do something else than what it was doing (good or bad) I have thrown everthing an the ketchin sink at this bike that's why I'm here.....I have built many dirt bike an atv engines. an never cam acrossed something like this that I couldn't figure out

after double checking the ring gap was .034

82 kz250l wrote:

swest wrote: Piston, bore, valves, bike.
Steve

Here's the bike I'll get the rest tomorow

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650ed wrote: That gap by itself is not going to cause the problems described. Is that gap the result of worn rings? Maybe, but I don't see how anyone would know that answer without seeing the rings unless they knew what the gap was set to when the rings were new; it may have already been set wide. Ed

I know the gap is not causing the problem....the gap is telling me the rings are worn out.....in the past where the ring gap was in my liking. And the engine had low compression I have re honed the cylinder an used the rings over again. In situations like that I have figured out loss of compression is from the cylinder glazing

From the look of the bore, the rings were "chattering". Put the piston in the bore and use a feeler gauge to measure the clearance, top, middle and bottom. If all good, do a cross hatch hone with 180/220 grit stones. By the look of the RTV, someone was in there before. New rings, valve guide seals, a valve lap and gaskets, it should run.
Steve

Time to start a new thread in the engine section. Can transfer the bore and piston there.
Steve

I moved it back to the Engine forum.
Bill