I am doing 3 of the 3250's but will put a needle bearing in the rod and a hard pin in the crank , my .90's are turning an apc prop 15x4 w 10500 on average and my 2300 is flying a 1/4 scale edge ( WH ) like a rocket , never have tached it lately but have probably 4-5 gallons of 50:1 klotz synthetic from day one .