Yet another cavitation thread, help with pulling pump

[yall_mahaw]

We took the boat out this weekend and from the moment we left the no wake zone by the ramp started experiencing some cavitation on the starboard pump. I am assuming this is cavitation, it felt like the clutch was slipping in car with the revs going up and down on the starboard engine. We stopped and I checked the clean out port, all looked good there, was not able to find any debris.

With the boat out of the water and looking from both underneath and through the pump gate, I was still not able to see anything that I thought would cause the issue. After reading through numerous posts here on the subject, the most common advice seems to be 'pull the pump' So tonight, I started to pull the pump. The issue, which probably isn't an issue, that I am having is getting the pump housing to separate from the hull. I have included two pictures that show the state of the pump, as a picture is worth a 1K words. Do I just need to eat my spinach and pull harder? Is there a spot that I am missing to use a small pry / screwdriver blade like there is on the jet nozzle? Appreciate any tips or tricks on this!

Last question, if I do not find anything when I pull the pump out and inspect the wear ring / impeller - what is the next thing to look for?

 

[Cobra Jet Steering LLC]

If this started after the boat ramp it is usually from backing in shallow water and getting things in the pump OR around the driveshaft like just a piece of fishing line.
Check the drive shaft and see if there is anything on it and you may also have something up in between the blades where you can not see it.
To answer your question there are special pry spots to use a big screwdriver to pry on but I seriously doubt you need to pull your pump .

 

[FSH 210 Sport]

Get a small pry bar like this and use the 90° end to pop the pump free. Feel around the edges and feel for the overhang and use gentle pressure around the pump, increase pressure as necessary and it will come off. Mine was on there pretty snugly with the sealant used during assembly.

The sealant used at the factory is different from what the service manual specs, the service manual sealant stays tacky and pump removal is much easier with the service manual spec’d Loctite product. You’re also going to need the molybdenum disulfide grease for the splines and the Loctite thread sealant for re assembly. I use a tap and die to clean the old sealant from the threads and out of the threaded holes otherwise at least in my experience you won’t be able to get the pump(s) to seat properly using the specified torque of 30 ft lbs on the four main bolts.

 

[drewkaree]

Try to hold the pump while prying, or fashion some sort of support for it, as it may drop down once you've done what @FSH 210 Sport recommended above, when it finally gives way. There should definitely be a gap between the two black "plates" in the area of those red arrows, and once you get the pry bar in there, if you're like me, you'll wonder how you didn't notice that earlier

While you're in there, check the tunnel to see if there's anything that might be contributing, like missing sealant or at least a less than smooth tunnel.

 

[yall_mahaw]

Appreciate the replies!

@Cobra Jet Steering LLC - I have looked all over for anything around the shaft, inside the impeller, and have not been able to find anything. Pulling the pump was a last resort option to see if there was anything that I just couldn't see externally hiding in there.

@FSH 210 Sport Appreciate the hint. This is the first time I have pulled the pump and was approaching the operation as cautiously as I could. I already have the grease and the 518 Loctite ready to go. I am hoping that I find something in there, not really sure what could be the culprit if not.

 

[FSH 210 Sport]

Appreciate the replies!

@Cobra Jet Steering LLC - I have looked all over for anything around the shaft, inside the impeller, and have not been able to find anything. Pulling the pump was a last resort option to see if there was anything that I just couldn't see externally hiding in there.

@FSH 210 Sport Appreciate the hint. This is the first time I have pulled the pump and was approaching the operation as cautiously as I could. I already have the grease and the 518 Loctite ready to go. I am hoping that I find something in there, not really sure what could be the culprit if not.

Don’t forget the Loctite 572 thread sealant as well!

Amazon.com

Cautious is good!

Check the impeller blades carefully for any dings or deformations, there was a member here recently who had grounded his boat and was experiencing cavitation afterwards and found that his impeller blade had a decent ding in it.

 

[Cobra Jet Steering LLC]

When you get the pump off before you disassemble anything further, Hold the driveshaft and spin the pump housing if it spins freely and you don't feel any spots where it is binding up it is probably fine. If I was betting I would bet that something was in the intake and it fell out when you took the boat out of the water if you don't see it now.