My 23 Kawasaki is not running right. Ive got a 52" exmark that is about 1 yr old 275 hrs. No problems other that changing the prefilter each day to keep it running good. Last week it started losing power for no reason. It runs like it has a clogged up air filter. It would barely cut grass then it would run fine for a while then back to the above. My dealer really couldnt find what it was so they put a new ignition coil in it. They thought it sounded like it was running on one cylinder. Air filter is clean and plugs were fine. So I get it back 20 yards later and it starts again. I take it back to the shop and it runs perfect, I cant get it to act up for the dealer. They run all kinds of tests but cant find anything wrong with it because its running fine. They tell me to run it until it wont run anymore so they can diagnose the problem. This is agravating trying to run a mower that is running at %75. This is my first Kaw and Im not impressed at all, if I could buy it again, it would be a kohler motor. All my other mowers were kohlers and never did any maintenance except oil and filters. I like the exmark but hate the Kaw. The dealer checked compression, carb, running temp, spark, and a couple of other tests. Any suggestions would be appreciated.