My 2004 FX Cruiser H.O. with appox 60 hrs.has lost it's full power. I used to get 58 to 60 mph, now I can only get 40 - 45 mph. The engine seems to run smooth and idle properly. I put in new spark plugs and checked for debris in the intake to no avail. Does anyone have any other ideas for a fix? Also the rpm limiter in not engaged.