I dont think the critical issue here was overheating (though I did not take an engine temperature reading, may be I should have). When I finished the fuel at the end of the day, the engine was at 60 deg after a minute of so of running, but that was mainly at idle . Note that he tightened the head bolts more. No idea how much that helped but it seemed to.

I noticed that even at 60-70% power with the 12x8, the hover could not be held. But she wouldnt climb either (if the power is sufficient, she should climb, shouldnt she?). Therefore will try a 13x4 on Saturday. I have also replaced the cowl. I am trying to lose some weight on her, will try 2.74" dubro diamond foam wheels, there is nowhere else to lose weight. Remember, I havent set the CG with this larger 320cc flexitank either, I just flew to check the engine

Ameyam