I am going to go check out a 2002 GTX with 155HP 4tec with 85hr on the motor this week. What kind of RPM's should I be looking for on the tach with only me on it (180lbs). ALso what kind of numbers on the top end should I be looking for on the speedo? I know they read a little high.
I ended up buying it. THe previous owner let me spend over an hour on it yesterday at the local lake. It ran strong all the way up to 7500RPM and is in really good shape. I feel I got a good deal on it ($4K with Zieman trailer)and had no major concerns with it. There were a couple of minor things I noticed however.
1) When I first started it it fired right up but there was a noticeable knocking sound resonating through the hull. I couldn't tell if it was coming from the motor or pump area. It idled around 1600RPM (is this normal?) but as soon as the idle came up to the 1900RPM range the knocking sound went away. I'm not sure if this is normal on Seadoos or what would produce the sound. Possibly a counterbalancer on the flywheel or something on the pump but as I said it quickly went away as soon as the RPMs came up off idle. Maybe its just a matter of turning up the idle a little. Can this be done?
2) There was some slight cavitiation when taking off from a slow or dead stop up until the boat came on plane (~20MPH). RPM's would quickly come all the way up to 7500RPM range. Once the boat came on plane it hooked up and pulled really well up to top speed. I don't think the cavitation at low speed (full throttle) is normal. I looked over the pump assembly really well from both sides before it went in the water and could not see anything out of the ordinary. The prop looked like new and had no sign of damage. I believe there is a replaceable wear ring that surrounds the prop but am not quite sure what to look for or how to determine if it is the cause of the cavition or needs replacing.
