I am looking at a 1997 Seadoo SPI and it currently does not have an engine in it. Does this hull accept the 787 engine?? I have one and if it does, I want to make it work.
First... anything can be done... but it will be a lot of work and $$$ to make it happen.
Next, Was there an "SPI" in 97 ?? I can't find anything on it. In 97 it looks like a SP or an SPX.
Regardless... if it had a 720 or smaller engine... those engines are interchangeable, and the MPEM will even work. (mostly) If you want to put in a bigger engine... you will need to make up the mounts for the engine, mod the exhaust, and need to use all new electronics.
If you want a boat with the 800 engine in it... part out the one you have... and buy an SPX, or 800 XP.