Cavitation problems!?!?!? Help!!

jonoman69 · Jun 17, 2013

I have a 97 crownline ccr210. 5.7 mercruiser. I'm running a 4blade 18 merc prop. I'll be cruising along at about 26 mph, with the drive barely trimmed up, defiantly not trimmed up to much. The boat seems to just start cavitating out of no where and this keep happening, the prop is brand new and does not have a rubber hub so that is not slipping. Anything that could be causing this?? Getting to be a pain

Bondo · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

jonoman69 said:
I have a 97 crownline ccr210. 5.7 mercruiser. I'm running a 4blade 18 merc prop. I'll be cruising along at about 26 mph, with the drive barely trimmed up, defiantly not trimmed up to much. The boat seems to just start cavitating out of no where and this keep happening, the prop is brand new and does not have a rubber hub so that is not slipping. Anything that could be causing this?? Getting to be a pain

Ayuh,.... My guess is the Coupler is failin',... Pull the drive. 'n have a look at it,...

tpenfield · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

Cavitation or ventilation.? You could verify the outdrive position versus the gauge readings

jonoman69 · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

Bond-o said:
Ayuh,.... My guess is the Coupler is failin',... Pull the drive. 'n have a look at it,...

Might be a stupid question but what exactly do you mean by coupler?

And it is barely trimmed up. It's only a hair up on the trim guage. Sometimes not even trimmed.

jonoman69 · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

I also did have the drive off this year to do the universals already. The splines looked fine on the shaft and when I punch the throttle taking off it doesn't do it.

ba5e · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

Can you smell any burning rubber at the aft of the engine right after the cavitation symptoms? Is the drive coupler housing hotter than normal, ie hot?

Bondo · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

jonoman69 said:
Might be a stupid question but what exactly do you mean by coupler?

And it is barely trimmed up. It's only a hair up on the trim guage. Sometimes not even trimmed.

Ayuh,... The coupler connects the motor to the drive,....

Did this just start happenin' with this 4 blade prop,..??

Did it do it with the previous prop,..??

Is this prop the Right prop for the drive,..??

My 2nd guess is, it's on Outboard prop ya put on,.....

cedgo · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

Put the old prop back on. If that solves your problem, you know the new one isn't right.

jonoman69 · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

I don't smell any rubber burning. And Im pretty sure it did it with the other prop. I know this is the right size prop for the boat. If it was the coupler wouldn't it be doin it more so when your getting on plane?? That being the most pressure on the drive and motor?

Don S · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

If you had a bad coupler or a spun prop hub, you would never get on plane, probably wouldn't get the rpm above idle before it slips.
If it is doing this only at higher rpm, then you have a prop problem. Go back to your original prop and see if the problem goes away.

jonoman69 · Jun 17, 2013

Re: Cavitation problems!?!?!? Help!!

Would a little bit of barnicle residue on the drive and bottom of the boat do it??

jonoman69 · Jun 18, 2013

Re: Cavitation problems!?!?!? Help!!

Would a chunk out of my skeg cause cavitation??

Cavitation problems!?!?!? Help!!

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