Sounds like my KLX. Mine always smokes on start-up for a minute and then clears up. I know its the valve seal(s). It has been like that since I owned it, since 2007. It only does it if I let it sit for a week or more without starting the engine.

 

If it only smells like gas, not likely it's a head gasket, especially if it clears up after warm up. Just wondering has it been hard starting? Can get some smoke just from overly rich starts too.

 

It's the valve seals, I'll bet a case of beer on it.

 

NOT a head gasket...but if you were joking, haha

 

white smoke is water. either condensation or coolant leak.
When it warms up the aluminum expands and seals off the leak (if there is one)
I have an exhaust leak on my truck at the header and head, for 5 minutes until it gets warm and goes away due to heat expansion.

 

I thought a new pope was elected when i clicked on this thread. I found out it was just a head gasket (sigh)

 

if it smells like gas it could be gas. checked gas in the oil. couid be a bad carburetor float valve needle?