Originally Posted by DLCS
His air filter will be the large round kind. I'm betting money its only running on one cylinder.
You may be right DLCS, But I looked at the fact he said it idled fine and ran fine at high speed thus discounting running on one cylinder because a twin will not do this, There would be a definite change in engine speed and sound.
As for the air filter I have no way to tell which style he has other than what Kawasaki shows. If it is the one posted,The wrong filter installed will indeed let the engine run properly for a short period of time until it collects a small amount of dirt THEN cause a rich burn lack of power under load situation.