HELP? Cavitation after changing wear ring and impeller.

[dwall2181]

Hi guys,

Racking my brain trying to stop a cavitation issue on a 2006 Yamaha SX210. On takeoff, I get the rpm's revving without thrust on my starboard side for maybe 3-5 seconds before the impeller bites and the boat rides normally from then on up in speed. This got a little better (less slippage) after changing the impeller and wear ring out but cavitation is still there just with less of a delay in thrust.

Also, the intake grate is missing (broke it) and it's back ordered from Yamaha. (been waiting 6 months)

I can hear a "pinging noise" when the impeller hits the wear ring when I run out of the water.

What should I try next to stop this cavitation?

I thought about changing the Jet Pump Bearings out next?

How do you know if it's the Jet Pump Bearing or the Intermediate Bearing?

Appreciate your insight!

 

[FSH 210 Sport]

Hi guys,

Racking my brain trying to stop a cavitation issue on a 2006 Yamaha SX210. On takeoff, I get the rpm's revving without thrust on my starboard side for maybe 3-5 seconds before the impeller bites and the boat rides normally from then on up in speed. This got a little better (less slippage) after changing the impeller and wear ring out but cavitation is still there just with less of a delay in thrust.

Also, the intake grate is missing (broke it) and it's back ordered from Yamaha. (been waiting 6 months)

I can hear a "pinging noise" when the impeller hits the wear ring when I run out of the water.

What should I try next to stop this cavitation?

I thought about changing the Jet Pump Bearings out next?

Appreciate your insight!

How old are your clean out plug seals?

Did you check the gap between the new impeller wear ring for proper clearance when you installed them?

 

[dwall2181]

Replaced clean-out plugs a year ago and they appear to be in good shape with a nice seal. I did not check the impeller & housing clearance. Can I do that with a feeler gauge?

 

[FSH 210 Sport]

Replaced clean-out plugs a year ago and they appear to be in good shape with a nice seal. I did not check the impeller & housing clearance. Can I do that with a feeler gauge?

Yes. When I put in my high altitude impellers I checked the clearance and filed each blade to give .014” of clearance.

You mentioned the intake grate being broken…that may lead to some cavitation as well…