550 to 750 pump/engine conversion

[jiwgallagher]

I was wondering if anyone out there has ever put a 750 pump in their 550 after making the engine conversion, and if so what did it entail. Do you have to swap drive shafts. I know that the intake and housing need to be cut out and made bigger, but I was wondering if there were any other necessary modification. Thanks for any help.

[john zigler]

Re: 550 to 750 pump/engine conversion

many years back, i had a modded 750 in a 550 hull. i ran a blueprinted 550 pump, with a custom built scat 19p prop. it was a ported, dual carb, 215PSI compresion, race gas only motor. this ski ran about 53 to 54 mph on GPS. it was as fast as i wanted to go on a JS hull. i know i could have tweeked a few more mph out of it with some botom blueprinting.

i have heard of guys putting a 750 pump in a 550 hull. it will take alot of work, but will help you utilize the full HP potential of the 750 engine. ( a 550 pump, with a 750 motor, is like a big block 427 corvette, with small 13" skinny tires).

i would recomend posting over at www.pwctoday.com under the vintage section. (this site is now also owned by SBT) i am sure you will get some ideas over there. good luck. zig

[jiwgallagher]

Re: 550 to 750 pump/engine conversion

Hey john, thanks a ton for your reply, I'm gonna take your advice about pwc forums. Also, looking forward to that pole bracket, the check is in the mail first thing in the am. thanks again
james ian gallagher

[john zigler]

Re: 550 to 750 pump/engine conversion

well, hello james. sorry, i didn't realize it was you.

let me know if i can help you at all. zig