My new TH .75 would not turn over at all unless i preheated the head, i also mentioned this in a previous post about the TH.75 so maybe thats where he got it from, i'm telling you i couldn't turn it over putting pretty good pressure on a 12" prop, even with 18V on my starter it still would not make a revolution, i preheated the cylinder a bit with a heat gun and it started right up, 2 tanks later the preheating wasn't necessary and it has run like a dream since, it is only 1 of my two engines that always start easily with a chicken stick ( the rest prefer a starter ) and is still really tight at TDC after a few gallons.