Shop Discount Sea-Doo Parts

Changing Crankcase Oil - 947/951 engine


New Member
Water Crafts
Seadoo GSX Limited 1998
The one you have is perfect. Just means Heavy Duty, basically marketing.
I’m in the process of doing this to my 951, and this last owner must have been a nut with a bad mechanic, because the bolt for the case oil was totally missing and the oil is badly water fouled and dirty. I got a replacement bolt and have been trying to flush the old oil with new, crank it, pull it out, repeat. But I don’t think I’m doing this efficiently because the stuff coming out is nastyyy. It also doesn’t want to take a full 40ml like the guide here says- it’ll barely take 10 before it won’t take any more. Maybe just trapped air? Any thoughts on flushing this stuff out? I need something that can emulsify the water and oil so I can suck it out. I thought seafoam but since it’s for the crank/counterbalance I don’t know if that’s the best idea.
Last edited:


Premium Member
Premium Member
White Lake Township, Michigan, also some in Braden
Water Crafts
96 GTX , 99 GSX Limited, 19 ft. Glastron I/O boat.
A hole being blown out of your cranckcase :)

I am not sure you can tell without checking the oil, and in your case with the '96 engine, this would mean you would have to split the case.

Perhaps using a mechanics stethoscope would allow you to hear an abnormal noise from your gears if they are getting chewed up like in the pics from this thread: 1999 GSX Engine Blew-what could have caused it? Pics

Of course, you would have to first know what the "normal" sound of the gears would be.

Thank you, For whatever reason I got an email about this thread. So far thru end of 2018 the ski runs great. Even though I retired last nov 2018 I didn't even put it in the water this yr :( ......Too busy selling Amsoil.....but I did ride my GSXL in FL. several times.

Users who viewed this discussion (Total:0)



Administrator Moderator Premium Member