Motorcycle has blue smoke coming out?

Question

My dad's motorcycle is a 1989 Kawasaki 250. It has a lot of trouble starting up, and when it does, blue smoke comes out. What could it be?

Answer 1

Black is unburned gas (sorry rockbase)

Blue is burning oil

White is water

Answer 2

If the bike is a two stroke, blue smoke is normal.  Two strokes have oil mixed with the gas and are usually smokey, especially on start up.  If the bike has been sitting for a while, or the mixture of gas and oil is too rich (too much oil, not enough gas) it will smoke too much and will give you problems with starting.  Try changing the gas out for new stuff, with a mixture of 30 parts gas, 1 part two stroke engine oil.  A new plug will help with starting too.  If the bike is a four stroke, disregard everything I have said.

Answer 3

black is oil, white is water, blue can be oil leaking from heads into cyclinder (valves) , bad rings or excess gas. if it goes away after running a few minutes id say you have oil leaking from valves into cyclinder

Answer 4

Is this a 2 stroke dirt bike? If so the blue is ok. On a 4 stroke blue is kinda like unwanted as it usually means a top end overhaul. This isn't the end of the world if dad can do it. Otherwise maybe $300 at the dealer.