Re: Evinrude Prop
Define back better. If it is a thru-hub exhaust and it is a piece that goes on the hub where it enters the gearcase, this is a matching ring that makes the hub diameter match the inside diameter of the gearcase so exhaust will not blow out over the hub and ventilate the prop blades. Simple piece but necessary for proper performance.
No Frank. This is OMC's diffuser ring. Back in the '72-3 era, OMC came out with a SS teflon coated prop with a brass/bronze (one or the other) diffuser ring pressed onto the rear. So you had this black prop and this gold ring....looked nice....I bought one of the first....$185 and that was when $185 was a lot of loot. Put a pleasant end to the constant bashing my 125 would do to aluminums, which at the time were the only available props.....well I guess you could have gone to Michigan Wheel and have gotten a bronze one but I had other fish to fry at the time or just didn't think about it till I saw the first OMC SS.
Merc already had the SS out and it diffused the thru hub exhaust with a flare as it does today. Welllllllllll OMC couldn't be like Merc so they diffused water into the exhaust with this ring. over time you'd see props without them as they stuck out half inch from the outer hub and were just asking to get whacked. As far as performance I never heard one way or the other. I never knocked mine off so I don't know from personal experience.
The front of the prop was notched (machined groove) to fit inside the lower unit housing.
-----------------
