Oil Smoke Starting?

I have a 76 KZ900, stock carbs and air box. When the engine is cold and the choke lever is on full, I get a large amount of oil smoke out of the exhaust till I get it off choke. The higher the oil level the more the problem, it seems. The oil level is corect. What goes?

Smoking exhaust at start-up often results from old hardened valve seals.

Isn't considered a significant problem, and usually vanishes after engine runs a short while.

Valve seals are inexpensive and could be replaced as and when the head is removed for some other reason.

Click > KZ900 valve seal from Z1E

Good Fortune!

If it only does it with the choke on, it could just be dark exhaust from running so rich.

Patton,

I think you have it right.

When I start the engine cold, I need to go heavy on the choke / sweetner and this causes the engine to race up to 3,000 to 4,000 rpm. With the slides nearly shut, the vacuum in the intake goes way up and sucks oil in through the valve seals.

Once I get it off choke, there is absolutely no smoke.

No eBay APP ID and/or Cert ID defined in Kunena configurationPatton is right about the stem seals. However I would not replace it with the stock Neoprene seals. I would go with the NEW Viton seals. They are only a tiny bit more expensive but are much better. I buy mine from Joe Hooper at Pitstop Performance.