Prop vent ring

I bought a prop while gander was closing out in La Crosse, it came with a plastic snap on ring (vent ring). Without going out the the shop pretty sure it was a Michigan wheel vortex prop. 4 blade just like the spitfire prop I’ve been running on the outboard (2001 Mercury 90 hp 4stroke). I bought that one used from a guy and it’s not had a vent ring on it. Should it have one? I’ve been unsuccessful in finding a definite answer by browsing through what I can find on the internet, haven’t been curious enough yet to try contacting Mercury directly.

Both props are aluminum FYI.

Put your new prop with the vent ring on. If you trash that prop put your old one on and use the vent ring for that one.

Doesn’t answer your question but my free advise didn’t cost ya a nickle either. Anyway, i’ll wait to hear what real advise you get.

IMO, vents are a personal preference thing. The shop that I bought my SS prop at offered to drill vent holes in my hub if I wanted. I chose to go with the prop as it was out of the box. What advantage do you believe you are getting with the vent?

Vents allow the prop to slip at the start to get the rpms up into the power for a better hole shot. Think of them like a stall converter. I have all the plugs out on my bravo 1 FS prop. Much quicker to plane

Are prop “vents” different then prop “rings”? OP asked about a ring which I took as being different from prop venting. I’m not a prop expert by any means so am curious to find out.

This is pure speculation, but I know when I had a tempest plus vented prop on an etec compared to the verado. The two stroke was way more affected by the venting. Even with all the holes plugged on a tempest it still slipped with the etec. Maybe the plastic ring is to cut off all venting if you don’t want it. Someone here should know for sure.

Hmm, did some reading and sounds like that ring is to help reduce venting. I’ve not really had an issue with venting, maybe once or twice when I try turning tighter than I probably should have. Will have to play around with it some and see if I notice much difference.

the prop vent ring is used to prevent excess exhaust gasses escaping from between the lower unit and the prop causing the prop to slip on acceleration or in turns.
if your boat gets on plane quickly now most likely you dont need it but if you are experiencing extended planing or slip in turns give it a try and see if it helps out.

if the venting/slipping you experienced were during really tight turns most likely that was due to blow out.
trim/raising/lowering motor height helps with that,or at the very least not turning so tightly during higher speeds.