Smoking Symptom (Your Toughts)

[studebakerjim]

The engine smokes heavy on start up the goes away after a few moments. Would this more than likely be a bad exhaust valve seal?

I would thing a ring or bad cylinder walls would be ruled out since it goes away.

[mi500]

liquid or air cooled motor? what color is the smoke? valve seals might be it.

[studebakerjim]

It is an air cooled 185S. The smoke is from oil and not fuel that I do know.

[jb2wheels]

Valve seals and/or guides. The let the oil seep in when it's cold and it pools in the cylinder for lack of a better description. Probably actually burning oil all the time but only a little once it burns off on initial startup. You might notice some when coasting, too.

The 327 in my Chevelle did that - smoke on start. When I had it apart last spring for a cam swap, I changed the valve seals. The old ones crumbled almost to dust.

Not an easy job, but straightforward. Not sure about the little singles but I did the work on the Chevy without pulling the heads.

[1984 honda 200s]

valve seals, or too much oil or worn piston+ rings or maybe cylinder wall scoring

[RubberSalt]

I'm going to go with valve guides, my KLT200 does that exact same thing and it's got a new bore. I only changed 1 guide, i guess i changed the wrong 1 when i rebuilt it lol. It still runs like a bat out of hell, and it doesn't burn much, i change it before it gets low anyways. I'd say do a compression test when it's cold. If it's low, it's the rings. If it's extra high, i bet you money it's the valve guides. That oil pooling in there dripping down the valve guides will raise the compression when your getting a reading. A true test would be a leak down, I'm not to familiar with the 4 stroke leak down testing though. But what i do know is this. Put the engine in the compression stroke bdc, Use air compressior and pressurise cylinder through the spark plug hole. If it leaks around valve guides/valves, you got a leak there. You should lose some psi due to the rings. If you raise the piston, apply pressure and it drops rapidly, then your bore is either scratch or worn out.