Questions about plastic ring on OMC alum. props

[farginicehole]

Can anyone tell me what the large (probably 5" diameter or so) plastic ring is around the rear of these props is for? My original 15x17 OMC aluminum prop has one, and it is on the prop facing the opposite direction as the 14 1/2x19 OMC aluminum prop I just picked up used. If I knew how to post a picture here, I would, but I'm sure you guys probably know what I'm talking about. Does anyone know the correct orientation of this ring? Thanks!

 

[Crownie2]

Re: Questions about plastic ring on OMC alum. props

Are they both rings, or is one just a flared end?

Bob

 

[walleyehed]

Re: Questions about plastic ring on OMC alum. props

It's called a diffuser ring, and is designed to pull(Help) exhaust gases out of the hub area. The widest part of the flare should be on the nut-side of the prop...the rear.

 

[farginicehole]

Re: Questions about plastic ring on OMC alum. props

They are both plastic rings, and the shape of the ring creates a sort of "flared end" on my 15x17. The ring is facing the opposite direction on this 14 1/2x19 though. A similar plastic ring on my '93 15-hp Evinrude is oriented like on the 14 1/2x19. I looked in a marine catalog at aftermarket stainless props and they don't have any ring like this - just a flared end like you describe. Thanks for the reply!

 

[farginicehole]

Re: Questions about plastic ring on OMC alum. props

Thanks, Walleyehead. It sounds like the one on my 15x17 is on correctly then. I wonder why the one on both the 14 1/2x19 and the prop on my 15-horse kicker are on the opposite direction? I wouldn't think that is something someone would remove and switch around for some reason. Maybe these diffuser rings do not come installed when you buy a new prop and so some people end up putting them on backwards? I'm not sure how easy it is going to be to take the one off the 19-pitch prop I just got so that I can switch it around.

 

[Silvertip]

Re: Questions about plastic ring on OMC alum. props

They can be worked off. Just heat them up a little with a hair drier so they become a little more pliable. Don't pry too much because they will crack.

 

[farginicehole]

Re: Questions about plastic ring on OMC alum. props

Thanks Silvertip, I'll give that a try.
I just don't understand how or why the other two props have them on backwards!

 

[xtraham]

Re: Questions about plastic ring on OMC alum. props

here's a pic if it helps..

 

[jimmbo]

Re: Questions about plastic ring on OMC alum. props

Newer V6 props have the rings mounted so the wide part is at the back.

 

[farginicehole]

Re: Questions about plastic ring on OMC alum. props

Xtraham, thanks for the pic. That is the way the ring is oriented on the 14 1/2 x 19 that I just picked up used on E-bay (and also on my '93 15-hp kicker). The 15x17 original on my '89 XP150 has it flipped around the other way, as Walleyehead and Jimmbo described. I guess I'll try and heat it up so I can flip it around, unless this really doesn't make a difference for the function?

By the way, how did you attach that pic to your post?

 

[Crownie2]

Re: Questions about plastic ring on OMC alum. props

This is interesting - so they did come both ways??

I was wracking my brain trying to remember which way I had seen them...

Bob

 

[xtraham]

Re: Questions about plastic ring on OMC alum. props

all my omc props have the deffuser this way, but they are all old,
to attach a pic use photobucket.com as a host, click on the litle yellow box above the reply box and paste the url from your photobucket account..........