Engine question.

[goin_divin]

Hi,
Can a Rotax 720cc engine be installed in a 1993 Seadoo XP? And if so, what modifications need to be done to ensure a good fit?
Thanks!

[Technical Support]

Re: Engine question.

You need everything.

[postal]

Re: Engine question.

That would make a fun ski I love my 90 sp wish i could put a 787 in there:emoticont

[Bill O'Neal2]

Re: Engine question.

It is a fairly simple task to install a 720 in a 1993 XP.

[goin_divin]

Re: Engine question.

One other question. Would any of the parts from the 657 fit it? i.e. carbs, etc...

[Bill O'Neal2]

Re: Engine question.

Yes they will, but you need to slightly adjust the carbs to use on the 720. The ports won't match perfectly, but you can either live with it, or grind them to match.

Use the stator and flywheel from the 657 on the 720. The exhaust from the 657 will bolt onto the 720 too.

[Technical Support]

Re: Engine question.

And after all that - you might gain 2 MPH :)

[Bill O'Neal2]

Re: Engine question.

But with a few minor mods, you might gain 5 mph or more!

[Technical Support]

Re: Engine question.

And by then you could have saved money and time and just bought a 3 year newer ski with 110 HP :)

[Bill O'Neal2]

Re: Engine question.

Whatever, but there is a decent gain in torque and overall power between a 657 and a 720 when both are stock and in good condition. For instance, ride a 1994 XP then ride a 1995XP 720, you can definetly feel the differences in both top speed and power to get you threre.

"IF" a guy can get a 720 motor in good shape, for a reasonable price, it is not a bad swap.

[Technical Support]

Re: Engine question.

All I'm saying is - that 'reasonable price' plus the work needed to do it, is often more than the cost difference between selling what he has and buying a slightly newer used ski.

I'm all for projects like this if someone just wants to do it for projects sake - or if they happen to have a parts ski already, etc. But starting from scratch just doesn't make much financial sense to me.

[goin_divin]

Re: Engine question.

This seems to have sparked a difference of opinion. Maybe this will help. I was given a 1993 Seadoo XP with an engine that has no compression in cylinder 1 and about 50 lbs in cylinder 2. I have an opportunity to get a rebuilt Seadoo 720 engine in the $500 range. My big question is, is it worth attempting to get this one running or would it be better to just buy a different machine from someone?

Thanks,
Tim

[Bill O'Neal2]

Re: Engine question.

You cannot properly rebuild a 657 engine for $500.

[Technical Support]

Re: Engine question.

For $500 IF the engine is in good shape and doesn't need anything else AND you don't need hundreds in other repairs to your existing equipment - that's a good deal.