I have the above mentioned motor, and have decarbed it and also use a fuel additive to help clear out the fuel system. Still having problems though. It is hard to start at first. After it runs for a while it does fine. I noticed also that while flushing the engine it cut off idling. Couldnt get it started for a while, finally did and it ran fine after that. The fuel filter is full of oil even with the motor off, possible clogged?