Time to rebuild the engine with all the new parts at last.
What oil should be used to lube parts during assembly.
Just the normal seadoo 2 stroke oil, or jetpump oil?
Different parts get different lube. The crank bearings you can do with 2 stroke oil. The crank seals(not the inner ones) and wrist pins get molykote 111. This is assuming you're doing a complete rebuild.
