Just finished my 1978 XR75 Engine rebuild. all new seals, new piston, new rings, cylinder smooth and in spec, rings positioned properly, re-lapped the valves.
The engine is running good, but it is smoking (white/blue). Lots when I rev it. I did but a little oil in the cylinder during the rebuild so that may be the cause, but I'm worried it is something else.
I did replace the exhaust valve seal during the rebuild (intake has no cam seal).
Ran it for about 20min, still smoking. How long does it take for the oil to burn out of the cylinder?
I check the plug and it was a little oily. Spit out oil spray when running w/o muffler then I first started it. Now I see a little oil seeping out of the exhaust muffler pipe seal.
Compression is OK (~120).
Do new rings and cylinder need to break in to do a good oil seal?
Is there any way to diagnose the cause before I drop the engine again and pull the head?