2003 kfx400 won't start will turn over but it won't start it has spark and gas but won't start it started for 2 minutes drove down the street and died out. It won't start again even with starting fluid. Held gas wide open nothing happened, it cranks but won't fire up. Some white smoke was coming out exhaust after trying to start for a couple minutes.

Check your spark plug for color, Tan, wet?
Try cranking with throttle wide open.

Check your spark plug for color, Tan, wet?
Try cranking with throttle wide open.

Yea I tried holding it wide open. Nothing. The spark plug was kind of black but no to bad

I would try a new plug, If you have spark, It would likely be in Carb or fuel. Air Filter?

I would try a new plug, If you have spark, It would likely be in Carb or fuel. Air Filter?

Yea it was sitting for a while becaese I had the engine and trans rebuilt. When we got the engine and trans back in the bike it started right up. Drove it about 50 feet and it died out. Then it wouldn't start back up even held wide open it cranked but wouldn't start? Do you think it could have something to do with the timing? Or valves? Cams?

I would suspect Carb from sitting, if you have points, they could be corroded.
It fires when points open.
Does sound like a fuel problem.

I would suspect Carb from sitting, if you have points, they could be corroded.
It fires when points open.
Does sound like a fuel problem.

Yea I think it's the carb or something having to do with the choke. What do you mean by points?

On older Bikes they had points which determined and delivered spark. You likely don't have them.
Be sure of kill and any neutral/clutch safety.
You may have a drain plug on float bowl that you could drain into a glass container to smell for bad gas and look for the presence of water/dirt.

On older Bikes they had points which determined and delivered spark. You likely don't have them.
Be sure of kill and any neutral/clutch safety.
You may have a drain plug on float bowl that you could drain into a glass container to smell for bad gas and look for the presence of water/dirt.

Yea. It has new oil and anti freeze and everything. The gas may be bad. But I think the choke is either stuck or the carb is clogged.