200x smoking

[madmass]

Ok well my X started smoking like a freight train. Figured it was time for a rebuild. Tore it down and the thing looks darn near new. Rings are still perfect top of the piston even looks really clean. Cylinder looks great. Very minimal wear if any. Head has very little carbon. However the exhaust port looks like someone filled it with axle grease. Valve seals? Bad adjustment? It's still the stock bore so it might have been redneck rebuilt (yes I'm a redneck) honed and reringed. I don't know that for sure.

[effort=results]

yup change out the seals. might as well do a full valve job while your at it. also might as well check piston cylinder gap .

[yaegerb]

Do a compression check. Then fill the cylinder up with a teaspoon of oil, then do another compression check. Did he compression rise? If so, bore and ring time. Axle grease in exhaust port? Sounds like valve seals need to be changed as well.

[jrooster]

Do a compression check. Then fill the cylinder up with a teaspoon of oil, then do another compression check. Did he compression rise? If so, bore and ring time. Axle grease in exhaust port? Sounds like valve seals need to be changed as well.

not to hijack, but my X has been smoking like a mother after a recent rebuild as well. Whats all involved in new valve seals? what does it ussually run a guy?

[yaegerb]

Depends on what shops charge/labor hour. You need a spring compressor and the new seals. I have all of this. If you are interested in getting it done, send me a PM.

[oscarmayer]

I would replace the rings, hone the cylinder myself with a bottle hone to just brake the glaze and do the head job. new valves, seals, and valve job. and probably web springs for good measure.

in my experiences is what causes this usually is a bad vale lapping job or worse no lapping job and stuff new valves on a used head and expect it to work w/o issues. this ruins the seat surface more and the new valves. what is going on is the exhaust is not closing like it should and during the compression stroke some fuel is escaping into the exhaust chamber and then it burns on the valve and the seat. the seat may now be pitted and trashed but you will have to double check with the machine shop to see if they can fix it.