Smoke on big valve engine
Posted: Tue Jan 18, 2022 3:55 pm
Hi all, got a mate with a big valve 130, same as ours. Engine smokes a lot when cold. Is certainly oil not fuel. If you rev it hard when hot it does a little bit, but nothing like when cold. When its warm I would think it is the carb pump jets just making a rich mixture for a second or two and washing the bores. Followed him up the road and there is no sign of smoke, either when pushed hard or on down shifts, so only when stood and cold. Still has plenty of grunt and goes very well. Motor was rebuilt, rebore, pistons, bearings etc around a year ago. Took it back to the builder and they did a comp. test. All plugs out, held on full throttle opening and turned with starter. Readings were all within a pound or two of each other at 185psi. Oil pressure is stable and where it should be. Engine has standard cams and Dellortos. Do these motors have problems with valve guide seals? Any other ideas very welcome. Cheers.