kecuki wrote on 07/21/16 at 12:13:41:

Hi guys. Thanks for all of the answers.

I put ~2 quarts, it's little below the "minimum" line if I check through the window, but I didn't run it enough to warm it up properly.

I didn't touch anything else. Bike is in dry garage, didn't hose it.

When I start it up, it runs and sounds ok, apart for the white smoke after while and terrible smell. Riding on 1st gear with no throttle for less than 20yards was ok too, but adding throttle caused coughing and almost stall, not good noises too. I shut it off immediately after that.

Bike is 1999, Ryca build, ODO says 700 miles but that's not the real mileage. I bought it used from decent looking guy who built it.

When you did the oil change did the oil have a fuel smell?

If the petcock is in fact bad fuel will leak past the rings and contaminate the oil. The fuel in the oil will burn-off at a very low temperature, causing smoke.

The petcock mod is probably a good move because it's a matter of when it will fail, not if.

Save trouble,swap petcock, change oil, know that engine is safe.

It's either foaming, or is contaminated.

doe it look brown?  water.

The bad smell is probably your pipe wrap... it does that.

It shouldn't be foaming at that level.

is that vertical or on the KS?

First, I idled the bike on stand for a while

That's not a good plan.
The cam starves for oil.

IIRC, the decomposition is only needed to relieve pressure so the cylinder can start moving to crank, and after that it serves no purpose when the bike us running. It may be possible that you have a linkage too short letting pressure leak out or air and moisture in, but that's just me spitballing because I don't see how that would cause smoking unless water or moisture was getting in there.

I would make sure the decomp isn't stuck open or something like that just to rule it out.

I don't know how pipe wrap works, but if it is new and uses that glue stuff like comes with exhaust repair kits could some of it have dripped into the header/muffler joint and it burning out?

BSTON wrote on 08/01/16 at 11:50:43:


There are 2 paths... thru the carb and thru the vac line.

Thru the carb means the float valve is bad or leaking.
Thru the vac line occurs when the petcock diaphragm has failed.
this leaks into the vac port of the carb and into the intake.

In both cases, depending on the slant of the bike, it could go into the airbox or engine.  once in the engine it will go past the rings and into the case.

It's Okay if you don't understand. But to choose to ignore people who have years of experience and know what the OEM Petcock does, isn't okay. Oil is cheap, the petcock is easy to swap.
Don't buy the cheapest one online. You Will get what you pay for.
Get a real one.