Smokey 250es

[atcmatt]

Gday.

FInally got round to rebuilding my 250es top end today with a new piston, rings, gasket set and bore job. I also painted it all up and tidied it up somewhat (pics will be to follow for anyone interested). Now on starting it up it was really really smokey and kept on blowing out loads of smoke for about 15 minutes on idle. I then took it for a little drive for about 2 minutes (not thrashing it, it has to be broken in) and stopped it, let it cool down a tad, and restarted it and the smoking was gone.

My question is it normal for the motor to run really smokey for a few minutes after it has just had a fresh top end put in it? What causes this?

Thanks

Matt

[stunter]

Rings probably needed to seat. also did you rotate the compression ring opposite the oil rings? It might be letting some oil pass which would cause it to smoke. Most likely the rings just needed to seat though.

[Howdy]

Rings probably needed to seat. also did you rotate the compression ring opposite the oil rings? It might be letting some oil pass which would cause it to smoke. Most likely the rings just needed to seat though.

It was also probably burning off any extra oil that was put on the cylinder when installing the piston.
Howdy

[Yamahauler]

I agree with Howdy
When I started mine up right after I rebuilt it, it was kind of smokey and fouled a plug up a little. I ran it til the smoke cleared and replaced the plug, now its perfect. I would say if the smoke has stopped, replace you plug.

[xman23]

your valve seals also might need replacing

[Tri-ZNate]

It was just burning off the oil. If the seals were bad it would still smoke like a SOB

[atcmatt]

Yep Thats probably what it was come to think of it! Cheers Guys!