Z1OwnersClub GB

you may already be bored with my help posts.
i need help in identifying source of oil.
No1 plug is black & sticky.I believe this to be oil not fuel as fuel would be black & dry.
The engine smokes the higther the revs.If it was valve stems it would smoke on closeing the throtel.So belive it must be rings.
Compression test results
1=150 2=165 3=170 4=170

If it was compression rings wouldn't it be pressurising the crank and blowing oil past the breather
Could it just be oil ring
How can i be sure

or could the valve stem oil seals

+1

Have fitted new stem seals.Would still then smoke on overrun.wouldnt it

put a teaspoon of oil in plug 1 and do the compression test again .. if there a big difference you have a ring/bore issue. Out of curiosity what head gasket did you use?

would oil in plug 1 show if its just the oil ring.I used a standard gasket.Didnt know it was a high compression engine till it was all back together

zman wrote:would oil in plug 1 show if its just the oil ring.I used a standard gasket.Didnt know it was a high compression engine till it was all back together

The oil just helps to improve the seal if there is a problem, head and barrels would have to come off for further investigation. Head gasket could be a problem. Have you re torqued it?

you could try a leak down test

did you check the valve guides for wear when you replaced the oil seals. what oils seals did you use? you could remove the carbs + exhaust + have a look at the valve stems to see if any oil is leaking down the back of the valves. you could have an oil leak between the oil way + the cylinder if its on no 1 or no 4

will do oil in No1 & try & rig up leak down test tomorrow.
I had been thinking that oil way may be leaking into No1,Not sure how i will check that