Hello all,
I've got a friend with this ski that has had several problems with it, finally has quit. Long story, too many details to list, but briefly....
This is a SBT motor-951 carbed.
Ran on pre-mix per SBT recommendations, with oil pump removed.
Runs fine, then runs poorly, parked.
Had carbs rebuilt by dealer and oil pump re-installed.
New trip, fitting on oil pump came loose, filled hull with oil, engine seized.
Next day, epoxied fitting back on, motor turned over, ran fine, fitting came off again 1 hr. later, filling hull up, seized motor.
Next day, ran pre-mix again, motor ran fine.
Different trip, ran ok, then poorly, found spark plugs didn't have threaded metal cap on them, fixed that, ran ok.
Found hull taking on water, lubed spline shaft?? water leaked sealed up, ok.
Different trip, put oil pump back on, repaired lube output fitting by threading a fitting on, sure not to come off this time.
Ran ok, then ran poorly.
Came home, did a compression test, 125 front, 70 rear. Disassembled and the photos show the rest.
Any ideas on the rear piston surface cause? Cylinder head? We're sure that the piston scuffing is from the oil starvation. Bottom end--not sure off.
Any suggestions about checking the bottom end since it was starved of oil?
Is this engine a candidate for top end only?
Many thanks,
Henry
I've got a friend with this ski that has had several problems with it, finally has quit. Long story, too many details to list, but briefly....
This is a SBT motor-951 carbed.
Ran on pre-mix per SBT recommendations, with oil pump removed.
Runs fine, then runs poorly, parked.
Had carbs rebuilt by dealer and oil pump re-installed.
New trip, fitting on oil pump came loose, filled hull with oil, engine seized.
Next day, epoxied fitting back on, motor turned over, ran fine, fitting came off again 1 hr. later, filling hull up, seized motor.
Next day, ran pre-mix again, motor ran fine.
Different trip, ran ok, then poorly, found spark plugs didn't have threaded metal cap on them, fixed that, ran ok.
Found hull taking on water, lubed spline shaft?? water leaked sealed up, ok.
Different trip, put oil pump back on, repaired lube output fitting by threading a fitting on, sure not to come off this time.
Ran ok, then ran poorly.
Came home, did a compression test, 125 front, 70 rear. Disassembled and the photos show the rest.
Any ideas on the rear piston surface cause? Cylinder head? We're sure that the piston scuffing is from the oil starvation. Bottom end--not sure off.
Any suggestions about checking the bottom end since it was starved of oil?
Is this engine a candidate for top end only?
Many thanks,
Henry
