How important is a cavitation ring?

[jwaldrop]

I bought a used fiberglass boat with a Johnson 35hp outboard motor. When I had it on the trailer someone told me that the cavitation ring was missing from the prop. What kind of problems will that cause me? Are they easy to install yourself?

 

[jtexas]

Re: How important is a cavitation ring?

on some prop models the trailing end of the hub is flared out, serves the same purpose as the diffuser ring - without it, exhaust can bleed back onto the prop blades and causing ventilation - if that happens, the motor will rev up as the boat slows down - prop is turning but it's not pushing water - kinda like a clutch slipping - how did it do when you took it out for a test run?

 

[Barnacle_Bill]

Re: How important is a cavitation ring?

I've never seen one that was removable. I take it there is a gap between the back of the prop and the L/U?

 

[Molaker]

Re: How important is a cavitation ring?

Perhaps JTexas should have said aft of the prop.

 

[Barnacle_Bill]

Re: How important is a cavitation ring?

Perhaps JTexas should have said aft of the prop.

Yeah as I obviously got my prop turn around.

 

[jwaldrop]

Re: How important is a cavitation ring?

I didn't notice it acting as you described (like a clutch slipping) so maybe it is OK. Thanks.

 

[guy74]

Re: How important is a cavitation ring?

The diffuser ring broke off the prop I was using on my 60hp johnson. It didn't seem to make any noticable difference.

 

[Scaaty]

Re: How important is a cavitation ring?

Lots of the plastic ones broke off...just use it..then get a spare prop (ya need one anyway!!)..then see if any diff..I doubt it (and nothing cavitates forward..reverse maybe..jeezz, I run a hubless SS prop on my Merc)