Polaris SL 650 Jet Ski Top End Tear Down and Gasket Replacement -1992

In this video I’m working on my 1992 Polaris SL 650 triple jet ski. I had low compression and while digging into it, I realized my lower cylinder gaskets were blown out, possibly by ice.
I also find out that the engine is an SBT aftermarket 650, with good looking rings and nicely honed cylinder walls. I don’t end up doing honing or the rings.
It’s not an exciting video, but if you have an older 650 triple, hopefully this is helpful!

[@SolPeel]

I didn't see a base gasket on #3 cylinder when you installed it

[@NashwaukSteve]

Thanks for the comment

[@codyreynolds4955]

Hello i have a 95 i am currently rebuilding and had 100 on compression and was wondering if you ever retested after the rebuild

[@NashwaukSteve]

Hello- I actually wrote down the readings in a note on my phone before and after! There was very little, almost no change. Before the job: 105,105,97. After the job 100,100,105. I guess the rear one improved. My 1993 SL650 had all 3 cylinders in the 120’s. Never got the 1992 there.

[@codyreynolds4955]

Ok thanks ever where i look has different numbers did it seem your lower compression effected the performance ?

[@NashwaukSteve]

Unfortunately there was something else wrong with this jet ski keeping it from running well. I ended up selling it along with the 1993, so I never got the payback on that engine work…

[@Kenneth-vp6mp]

Check the service manual for acceptable compression values

[@alexholley3216]

Leave the other plugs in without the wire on wen doing a comp test on two strokes

[@NashwaukSteve]

Thanks for the comment

[@Kenneth-vp6mp]

The rebuild of the engine wasn't completed by the former owner. Whoever rebuilt the engine, didn't replace the piston and rings after reboring the cylinders. The cylinders get larger when they are rebored and oversize pistons and rings are required to maintain the compression. The rebuilder didn't want to spend or have the money to replace the pistons and rings and just slapped the engine back together after honing the cylinders.Then he/she sold it to you. Totally unprofessional!

[@NashwaukSteve]

Yeah that sounds right. It was a tough ski to own the whole time I had it. It’s since been offloaded and I saw it on Craigslist a couple months again after that.