motor swaps

[professorpg]

Will a 800 bolt up to what was a 717 in a 97-speedster?
It runs now, but would like to start putting up a pair of engines.
I find that the best way to learn about an engine is to set one up on a stand.

interested in any comments.

 

[seadoosnipe]

Curious!

I'd like to know if this works for you because I have the 97 challenger and I find the most frustrating thing in trying to go around the DESS system to power up the MPEM to start an engine........so I'd be happy to hear your results!.......

 

[JoeZ]

I really can't remember where I read it or why, but I think that 720 and lower can swap, and 800 and higher can swap, but not in between. I could be wrong though...and I think it has to do with the pump assembly but I just can't find where I read that or fully remember why.

I was considering doing something similar with my Speedster recently which is why i was looking. If either of you find anything, post it here.

 

[seadoosnipe]

Motors?

Like you, I don't know if you could swap out one size engine for another, but I'll see if I can find an answer. Logically, if the motor mounts, shaft and electrical system were engineered the same, then yes you could. But then you'd have to ask yourself if the hull, support and basic integrity of the boat could handle the extra horsepower. The stress of a hotter motor could be more than the hull's design could handle.....

 

[seadoosnipe]

Found your answer!

I found some technical data on the Rotax engines and it appears that no other engine would fit your application without a lot of modifications..........hope this helps!

 

[professorpg]

yep

I checked with Pery Performance (just south of Ft. Lauderdale) and they said no, not without a lot of modification. He said the 800s are also a lot heavier and he recomends building the 720s.

 

[seadoosnipe]

Great!

I'm so glad you were indeed able to find a good answer from an OEM certified mechanic before you invested too much time and money in on an engine change. Funny thing about these Rotax engines, they really look like there isn't much if any difference in them.