Rotax 717 and 720 reliability

Jimwhall

Petty Officer 2nd Class
Joined
Aug 6, 2013
Messages
190
Looking at a couple of 1999 Sea Doos. I'm just looking for a couple of years of fun with my older sons. I know these are old.

Sea test checks out. Hoses look good. Compression is good. Other than that, I've heard these gen Rotax engines have good reputations for reliability. Is this true? If I can get a couple summers out of them for the price I'd be okay.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
51,351
Published reliability 27 years ago means nothing. How were they maintained the last 27 years?
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,176
Looking at a couple of 1999 Sea Doos. I'm just looking for a couple of years of fun with my older sons. I know these are old.

Sea test checks out. Hoses look good. Compression is good. Other than that, I've heard these gen Rotax engines have good reputations for reliability. Is this true? If I can get a couple summers out of them for the price I'd be okay.
it does come down to how they were maintained, oil used and if they ran lean. If compression is still good that likely means it was reasonably cared for.

Not exactly the same engine but we just sold our 2004 GTI RFI LE (787 engine) with just shy of 300 hrs on it. We bought it with about 100 hrs 14 years ago, so fairly new. Always used the XPS synthetic oil, the chit is expensive ($60/gal) but we only used about 3 qts a year ...

I rebuilt the jet pump and wear ring twice. Had an issue with magneto and the exhaust manifold core plugs leaking , but basically was trouble free enough to keep that long. What finally tipped me over the edge was the crankshaft seals on the rotary intake valve started to leak oil into the crank case when not in use. Found this out the hard way when it was hydro locked this spring after sitting all winter( I had topped off the oil reservoir in fall). Engine still has about 145 psi compression , but to do the seals engine has to come out and take the crank out... so engine needs tore down.

I eeked through the season by clamping off the hose to the oil reservoir when not in use. Disclosed this when I sold it.

Bottom line if the ski has been reasonably cared for and doest look like a pile of chit for a small investment and some skinned knuckles you can get on the water.
 
Top