I had a 95 SPI.. same body stile (x-4 hull), and same motor.
The motor sizes for seadoos are 580, 650, 720, 800, and 951.
The first three use rotary valves and normal porting.
The 800 uses a rotary valve but also has rave valves on the cylinder.
The 951 is a reed motor.
All are two stroke, 2 cylinder.
The latest seadoo is called the 4tek and has I believe a 1500 cc motor making 150 hp but dont quote me. Also check out
news://rec.sport.jetski for more info
For hp ratings, weight, etc, go to
www.nadaguides.com and click the boats link to take you to your make and model. Yours has a 55 hp motor which is the same as my spi was. Small motor but it hauls and is a blast to ride on.
I have also owned a polaris sl 650 and a kaw 440 in the past.