1999 Sea-Doo Challenger 1800 Rotax 787

[JeremyD615]

Never take advice on oil from anyone that doesn’t specialize in Sea Doo. They’re almost always wrong...

You need a synthetic API-TC oil. Pull the hose off of the pump and let it gravity feed everything oout of the tank and lines. Clean everything out, and then open the bleed screw on the pump. Fill with oil and leave the bleed screw open until you get a solid stream of oil with no air. You can then close the bleed screw and let the motor prime the small lines from the pump to the manifold...

 

[Derek81]

Thanks!!

 

[Doug Overkill]

That thing was seizing before the ring grooves let go.

Glad to hear that you got yours back up and running. I am in the middle of the same experience. 3 holes measuring 145-150 psi and one @ 10 psi - tear it down and found same exact as your pics.

Hey @mikidymac - what makes you think that was seizing before the rings let go? I just tore down the right motor on my 97 1800 and the rear piston looks brand new. the Mag side piston looks just like the picture the OP put into post 20 & 22. What would cause this seizing? What do I do to make sure it doesn't happen again to my fresh top end?

 

[mikidymac]

Glad to hear that you got yours back up and running. I am in the middle of the same experience. 3 holes measuring 145-150 psi and one @ 10 psi - tear it down and found same exact as your pics.

Hey @mikidymac - what makes you think that was seizing before the rings let go? I just tore down the right motor on my 97 1800 and the rear piston looks brand new. the Mag side piston looks just like the picture the OP put into post 20 & 22. What would cause this seizing? What do I do to make sure it doesn't happen again to my fresh top end?

The black carbon on the top of the piston and scuffing on the sides.
Lean.