Hi, I have just purcased a Suzuki DT 140 (88) that have running fine for a couple of months. Now it have problems getting up to speed. When I get the throttle up to about half it starts to misfire( I think you use that word or won't go on all cylinders. It seem to have a fit of coughing back there. The idle speed is (in my opinion) also to fast and the idle speed switch on the side cover seem to have no affect. The engine starts on the first stroke. I have tested the comp and it is about 130 on all four cyl. New plugs is also installed. Could it be something with the egnition system - and how can it be tested?<br /><br />The engine also produceing a lot of smoke when it starts, but I have been told that that would get better if I use a fully synthetic 2-stroke oil. Any comments or experiences on this??<br /><br />Nice boat weather here in Norway this days, so this realy sucks...