Ok, I don't know what I'm talking about, even though I have the same engine, but could it have started up backwards and have been blowing out the carb? I've got the same engine, and after the first couple of tanks an instructor had to remove the limiter to get the engine leaned out right. Yours could be running rich and blowing a bit out the carb. I think you should try to repeat it with someone there who has more experience. Oh, and instead of putting on a bigger 3-blade prop, I took the baffle out of the muffler, and bought a metal 2 blade spinner, and a 11x6 2 blade prop for mine. Removed the flywheel also. Now the crazy Extra EZ 2 pulls off in about 20 feet even through a couple inches of slush.. - Joe