How to tell if jet pump is bad?

[Copious]

Trying to track issue in port engine. Engine is shuddering and won’t go above 2.5 rpm - have done cylinder test : all 120
Have done violent pressure test and all holding.
Changed spark plugs.

how do I check the following;
Impeller is working
Jet pump is good
Supercharger is fine (just done rebuild)

what else do I check before taking to the shop?

 

[WaTeRMaNiaC407]

Your subject says "how to tell if jet pump is bad" but in your description you say that the jet pump is good. How do you know it is good? I would look to see if there is something stuck in your pump and check to make sure that your impeller isn't bent and the wear ring is in good shape. Does this shuddering only occur when in the water?

 

[Copious]

I cannot see anything stuck in the pump or impeller - it is only when it is in the water that it shudders

 

[WaTeRMaNiaC407]

You most likely have something in your pump, a damaged wear ring and/or a damaged impeller. There could also be issues with your carbon seal. I would pull the pump first and inspect. It is not hard to pull it and there are several videos out there on how to do it if you familiar with the procedure. If your impeller is bent or damaged it can most likely be fixed by impros. Much cheaper than buying a new one. If you have it off, you should just replace the wear ring anyway. Good Luck!

 

[MacSeaDoo]

You have to pull the pump out to check on the condition of it. It is a simple job if you are all mechanically inclined.

You could also just pull the bucket and nozzle assy and then pull the cone to inspect the bearings without removing the pump. You can only do this if you are running grease instead of oil in the pump.

If the bearings and grease are clean, most likely the bearing side of the pump is fine.