[LexCorbett]

Hey guys!

After 8 months of reviving a 450 (enginewise - carb rebuild, total ignition system rebuild, valve clearance, timing chain tension, etc. etc.) I finally got it running. It'll run steady, however, it smokes. Good white puffs every stroke.
Where should I be looking? Valve stem seals? Piston and rings?

Have yet to formally check compression but from many intimate kicking sessions it feels solid.

Wear should I be looking first?

Thanks guys.

 

[76TWIN]

How long was the bike sitting before this?
I would check compression and then add a couple teaspoons of oil into each cylinder and then check compression again. If the numbers shoot up with the oil then you have worn or stuck rings. If nothing changed even with the oil then you likely have leaky valves or valve guide seals.

 

[doode]

You may try driving it a few miles to see if it clears up?

 

[J-T]

If the bike has been sitting for some time, I'd ride it. Monitor oil consumption and performance. If it runs ok ride a couple hundred miles, then check the compression. Smoke may well just go away.

 

[LexCorbett]

Been sitting for quite some time, my best educated guess (which is the best I can offer, I've only owned for 8 months) being 5 years. I was going to ride it and see how things cleared up but unfortunately I ran it dry of gas letting it idle and now it won't come back to life. Likely swallowed up a spec of something in the carb. So here we go again! My own fault.
Anyhow I appreciate the insights. When I get it going again I will ride it out and see what happens. In the meantime, I will do a formal compression check with the oil as per 76TWIN.