Kawasaki FH541 problem

[lwcmattlifter]

I'm having trouble diagnosing this engine. It runs rough and cuts out at cold idle at any temperature. Has a bad hesitation when throttle is applied fast or slow. The engine runs rough and has a small backfire at 25-100% throttle with the choke off. Under load the engine randomly loses power to the point it almost dies. It runs good with 1/4 choke. The spark plug next to the muffler is heavily carboned and the other looks normal, maybe a little lean.

I have cleaned out the carb, and tried running with either plug wire disconnected but the engine runs worse and the rpms drop so I'm assuming it's safe to say both coils are ok, right?

[Travis Followell]

It sounds like your coils are ok if the engine will run with either wire disconnected. If one plug is heavily carboned that makes me think its getting too much fuel. I had a briggs do this a while back. Had pretty much the same symptoms you are describing. I was in that carb 3 times and never found anything wrong and even rebuilt it and it didn't help. The guy it belonged to got another carb for it and put it on and it ran like new. Does the engine seem to be burning more fuel than normal? You could possibly have a valve problem if its not the carb.

[lwcmattlifter]

I don't think it's burning any more fuel than usual. I haven't run the engine much since it started acting up. This engine only has about 175-200 hours. I bought the mower in March 05.

[Restrorob]

If the engine runs fine with 1/4 choke I would say it is leaning out.
I would suggest going back through the carb. a second time just to make sure no passages were missed. Check the fuel cut-off solenoid if equipped with a jumper battery to make sure it pulls the plunger in all the way. If the problem still exist then check the intake manifold bolts and gaskets.

[xcopterdoc]

I've seen the Kaws bend a pushrod too. If all else fails.. remove and check em out.