2002 GTX D1 low top speed

[LFADAM]

My family just bought an 02 GTX D1 last week. Ive done some reading and gathered that the top speed on this PWC is about 50mph according to the speedo but that the speedo often reads 6-7mph slow. Full throttle on ours with just me (170lbs) only yields 43-44mph (at 6500-6510rpm which Im guessing is redline?). Im confused because it seems to be running well. No idle problems and accelerates quite fast. I am at about 35 mph at only 2/3 or so throttle but pinned only adds about 8mph. Is there a problem or is this just normal and this ski only goes about 45 not 55? I have a suspicion that the OPAS is not retracting at high speeds like it should as the steering still feels touchy and darty at high speeds. How can you tell if it is retracting or not (I cant exactly hang off the back and examine it at 40 mph) and what rpm is that supposed to occur at? Thanks

Oh and what kind of GPH or MPG is average for this PWC?

 

[Nate Surveyor]

OK, I don't know much, but I have been learning around here.

1.) PWC speedometers are often not accurate. Use GPS to find out what is real.

2.) It is possible that somebody put a "Take off" impeller on your Doo. That is, it is good for take off, but not for top speed. On boats the number goes like this: "A 13-15 prop" That means the for one revolution, it moves forward 15 inches, (assuming zero slippage) and is a 13 inch diameter prop.

3.) Cavitation is more likely a problem, but you know how it is. I live in Arkansas, and diagnosis from a distance can have errors!

4.) Also, you can have dings and stuff in the impeller, from sucking up rocks. Unfortunately, this is a popular activity, with the new owner of this kind of craft! This can drastically reduce performance.

Nate