'96 Speedster Oil Pump not working

[zonzik]

Two months ago I put my boat on the water and after 5 minutes running the starboard engine just died and didn't want to start. I took it home, cleaned the air box, filter (which was really dirty) and started the boat-no problems. Next time i put it on the water same thing-the engine died after 5-10 minutes. I took it to a Marina this time and they opened the engine-one of the pistons was damaged. Both engines had 135/135 compression before that. Well we put a new (rebuilt) engine and the guys checked the oil pump-it wasn't working. I purchased used one from eBay (the guy had sold over 10 all good) and we installed it. Same problem-it's not working. The engine starts and runs fine (we mixed the gas with oil) but this pump doesn't pump oil. Are we doing something wrong? Any ideas?

 

[Seadoobuddy]

did they check the "gear" that operates the oil pump?

 

[zonzik]

I believe so. I'll be there in couple of hours and will make sure. Sorry for the question but how to check the "gear"? Maybe it sounds silly but I'm not very familiar.

 

[Coastiejoe]

Two months ago I put my boat on the water and after 5 minutes running the starboard engine just died and didn't want to start. I took it home, cleaned the air box, filter (which was really dirty) and started the boat-no problems. Next time i put it on the water same thing-the engine died after 5-10 minutes. I took it to a Marina this time and they opened the engine-one of the pistons was damaged. Both engines had 135/135 compression before that. Well we put a new (rebuilt) engine and the guys checked the oil pump-it wasn't working. I purchased used one from eBay (the guy had sold over 10 all good) and we installed it. Same problem-it's not working. The engine starts and runs fine (we mixed the gas with oil) but this pump doesn't pump oil. Are we doing something wrong? Any ideas?

Carb adjustment is crucial as to when and how the oil pump operates.
Did you go through the bleeding process ?
There is a bench test that can be done as well.

If it isn't a total pain, I would swap the two oil pumps around and see if the problem follows the pump or stays on the same engine.

Here are a few pics that may help...

 

[zonzik]

You mean to change the pump from the port engine. I see. Never though about that. If they don't want to do that I'll do it.

 

[Coastiejoe]

You mean to change the pump from the port engine. I see. Never though about that. If they don't want to do that I'll do it.

Yep,,,

You have a HUGE advantage having twin engines. You have known good items. So as long as the labor isn't a deal breaker, swapping them will tell you what you are chasing...

If you swap and the oil pump works, then you know it is an engine issue. Such as a gear or line. If you swap and the oil pump does not work on the other engine, then you know it is in the unit...

 

[zonzik]

Will go with the other test first. I believe that they just checked the oil line and the oil wasn't moving. When the line is not attached to the pump the oil is going down freely. It's got to be the pump adjustment or that "gear" that the Seadoobuddy was talking about. The guys at the shop should know better than me. I'm afraid that they are not so experienced with jet engines...

 

[zonzik]

Just came back from the shop. The guy said that the gear works and he did some kind of "bleeding" on the pump. I gave him the instructions that Coastiejoe gave me and he'll do it again.
Well here is a picture of the damaged piston in the old engine. Just wondering if this could be oil related damage.