I have a 60 inch Exmark Lazer with a 27 hp licquid cooled Kawasaki engine with 1700 trouble free hrs. Last season it started to make a random piffing sound (best written description) most noticable at idle with some loss of power. I finally decided to address the issue this spring. So far I tried to spray carb cleaner around all intake gaskets when running to see if the engine changed tune but nothing noticable. I have changed spark plugs and cleaned the air cleaner. It really sounds like it is coming from the intake manifold and I have ordered gaskets. When I did a compression check one cylinder was 120 psi and the other was 115 psi. Is this a normal reading for this engine? Has anyone else had a similar experience? Thanks for any input!