1997 Seadoo challenger 1800 oil hydro lock on remanufactured engine

[Passenger413]

In 2023 my port side 787cc engine was hydro locking with oil. I decided to just replace the engine with a reman SBT engine with a 12 month warranty. I followed the recommended brake in process according to SBT & by the end of that season in 2023 my engine was broken in. The engine seemed to be smoking more than normal but was clearing up after about 10 minutes on the water. I had no issues starting or running that engine at that time, other than the excessive smoke. The next year In 2024 at the start of the season, I took the boat out a few times & the port side engine only was still smoking a lot. By this time my SBT warranty expired. I took the boat out for a holiday weekend & "click" no start on the port side engine. Pulled both spark plugs & found rear pto cylinder full of 2 stroke oil again causing hydro lock. I cranked the engine over for awhile & got a lot of the oil out & ran the engine. A few weeks later tried to start the engine again & "click" no start, hydro locked again. Pulled plugs again & a lot of oil comes out when cranking the engine. The SBT reman engine is supposed to have new crank seals on a remanufactured crankshaft & new rotary valve shaft seal. I have recently removed the engine thinking that the crank seals must be bad. Like maybe damaged or defective seals, or improperly installed. I tried to pressure test the seals & put 5-10 psi on one end of the oil fittings to the RV cavity & plugged off the other end. I forgot about it & left it pressurized for like 24 hours at 5 psi & when I remembered to check on it, it was still holding pressure at 5 psi. there is still oil in that cavity, so not sure if that will not test correctly. I don't want to just throw a rebuilt crank at it if it isn't going to fix the problem. I have searched the forums & the only thing I can really find says bad crank seals or rv seal. Any help or diag tips would be great.

 

[mikidymac]

You need to put pressure into the pulse line fitting and block off the intake and exhaust to properly check the crank seals. But if it is floding with oil it is the crank seals. You can try installing a shut-off valve on the oil line but it is only a bandaid, not an actual fix.

Oh, and if I haven't said it enough, stop buying anything from SBT, it is all garbage. Stop Buying Trash...

 

[burtshaver2021]

I wouldn’t normally disagree with Mikidymac but you tested the inner crank seals correctly by putting the air into the RV cavity oil feed line and blocking the RV cavity vent hose

 

[Passenger413]

I wouldn’t normally disagree with Mikidymac but you tested the inner crank seals correctly by putting the air into the RV cavity oil feed line and blocking the RV cavity vent hose

Is there anything else that would cause this issue? Before I split the case I just want to make sure I am testing everything I can to try to figure this out. Should the rv cavity be empty of oil before trying that pressure test? I think The pto cylinder still has oil in it too

 

[burtshaver2021]

Is there anything else that would cause this issue? Before I split the case I just want to make sure I am testing everything I can to try to figure this out. Should the rv cavity be empty of oil before trying that pressure test? I think The pto cylinder still has oil in it too

I’m sorry, I’m not aware of any other possibilities for the oil to get in there. I’ve had similar happen and I wonder if there is some type of valve in the area where the small oil lines go but I don’t know.
I’ve always had some oil in thr RV while testing the inner seals.

 

[mikidymac]

It depends on which way the lip of the oil seal is facing. If it is facing the cavity then pressure could make the seal actually tighter and not show a leak but it could leak under no pressure. You have a pretty major leak if it is filling back up that fast.