The enging spins the prop fine when we put it in gear. So fishing line isnt the problem. As for adjusting the carbs that might be the problem. We're also running bad gas from last year. weve added octaine boost and carb cleaner, we diddnt ad stabilizer last fall either.......The back pressure thing sounds like definate possibility.Originally posted by Upinsmoke:<br /> Did you by any chance adjust the carbs running the engine on muffs? If so, readjust them with the engine in the water. No back pressure on muffs. Check link&sync, then readjust idle mixture and idle speed.