Currently own 96 175 FastStrike M # J175GLEDB, S# G04061097. I had a power head changed this summer and I'm having problems with lower rpm 's and top end speed. Rpm's are down to 5200 from 5800 and top end 52mph from 60 mph. I brought it in to my mechanic; he found a small fuel leak and said it was running cool for that motor and needed a change in thermastates but doubted that would make that kind of difference. Is it possible I'm not getting WOT. What would you suggest. I also had compression check done and he said that all cylinders were at approx. 100 lbs.