I recently bought a 97 Sea Rayder 175XR2, 165 Hours, not run in the past year, starts/idles ok, comes on plane very fast, runs 5500 rpm at top speed. The problem is that top speed is only about 39 mph. I confirmed the speed with a gps. The bottom of the reverser is about .25 above the jet/nozzle while at rest at full throttle. I thought it might be the impeller or wear strip, but from this form it appears that impacts low speed performance more than top speed. 39 mph was with 2 adults in the boat, 350 lbs, and 1/2 tank of gas. The previous owner de-activated the oil injection so we are running 50 to 1 with some carb / engine ring cleaner at the moment. Any ideas anyone? Thanks!!!