This motor (Serial No. OB153661) idles OK (for a 3 cylinder)when in neutral, but when I put it in gear, it has a stumble, like possibly an ignition or fuel problem with one cylinder when the prop puts the motor under load. Even with this stumble, it has never stalled. The idle is set at 600 rpm (in gear, in the water). When I advance the speed to 900-1,000 rpm, the engine smooths out. At higher speeds,the engine operates great and has plenty of power. The fuel pump diaphrams, fuel filter and spark plugs have been replaced, and also the stator about a year ago. As a result of help from a previous post, I made sure all of the carb throttle plates were closed at idle, and enriched one carb to cure a lean backfire condition. The engine doesn't backfire anymore on starting, but I am still trying to fix the idle problem. Also today, I checked the entire electrical system for loose connections, but found none. Would sure appreciate any other ideas on how to fix this problem. Thanks
