1995 SP Cavitation / Pump Problem

[seascan]

Hi. I just took my SP out after sitting for a number of months. Last time I took it out it ran perfectly. Today it will not get over 10mph or so and seems to vibrate at that speed.

The impeller and wear ring "look" fine. I am wondering if it could be the neoprene seal.

Does anyone have detailed instructions on how to replace the seal? Any recommendations?

Many thanks!

 

[nswillin]

Rule of thumb:
High RPMS/Low Speed= Propulsion problem:wear ring, impeller, shaft, anything with jet pump

Low RPMS/Low Speed= Fuel problem: clogged filters, carbs leakin out, ect...

Which one do you have?

You can check the wear ring by using a feeler gauge through water intake. Remove grate and look through. Clearance between the wear ring and impeller should not exceed 1.0 mm (.040 in). Measure each blade at its center.

 

[seascan]

It's a high RPM problem. At low RPM it runs completely normal.

It doesn't look like I can fit a piece of paper between the wear ring and the impeller.

 

[nswillin]

If its revving up real high and you not going anywhere somethings up with the jet pump. Impeller could be bent or shaft could be slipping as well.

 

[seascan]

The strange thing is that it sounds like "a clutch slipping"... I do understand that my ski does not have a clutch!

 

[robin savell lloyd]

It does seem to be the neoprene seal as the boat had no isues before or it could be the carrier seals. I have had a broblem before with a bad vibration I just turned the engine off and restarted and it seem to be ok. I could only guess that I sucked somthing up at the boat ramp and it let go when I turned the engine off. The seal is easy to change you need to disconect any water line atached to the pump from inside the hull like a bailer line and the water line that cools the engine. [should only be 2 I think] Then remove the 4 bolts that hold the pump to the hull and any thing that is atached to the pump like steering and so forth. It may require a litle force to seperate the pump from the hull. [make sure you have removed all bolts before trying to pry away and becarefull not to chip the jelcoat when prying. Use a good sealent like the [right stuff] brand sealent sold at autozone or discounts auto parts to seal the threw hull fitings. good luck Robin :cheers: