Seized impeller?? Merc Optimax 250 Sportjet on Polaris EX2100

[NewtJ82]

I have a rare boat apparently (2004 Polaris ex2100), but it has a 250hp Mercury Optimax Sportjet, same as on some other makes I believe.

Was running it wide open down the lake, suddenly stopped pushing water through, with motor still running. Got towed back in, found no obstructions in the impeller area. Ran it on the hose in the driveway, impeller not spinning. Checked the gear oil in the drive housing, and it is basically all water with sediment in it, not much of any oil, if any.

How bad is this, and what am I looking at for repair? Will be taking it to my mechanic to investigate further, but just looking to see if anyone has experienced it and what I should be planning on.

Thanks in advance!

 

[tdonoughue]

Did you pull the pump to inspect the impeller, or just look around it? My initial thought is that probably you have something stuck in the impeller still (and it is, for example, on the other side or something). Doesn't take much lodged in there to gum things up pretty good as you describe.

Not familiar with the drive housing on the Polaris, but, yes, water in there does not sound good. Sediment sounds worse. It is possible it froze up and it is game over there. Just seems odd that it would not start to squeak or slow down or shudder or something before it stopped if that were the problem. Just my guess there...

But anyway, I would start by pulling the pump if that can be done easily on your craft (mine is 4 bolts, basically), to make sure there is nothing stuck in there.