What prop? I'm lost

[whydoihateboats]

Need help with choosing a prop for a 1992 rinker 186 with a 4.3 Yamaha. I'd like SS, it currently has no prop, I'm looking for just a good all around prop. I've had so many sizes and pitch suggestions and have no idea.

 

[airshot]

What is the max rpm rating for your motor ? What is the maximum RPM you are getting with your current prop. Without a starting point and rpm numbers, we can only guess....

 

[Stinnett21]

You can go online to the Mercury prop selector as a starting point, but as stated above knowing info up front will make matters better.

 

[Scott06]

Need help with choosing a prop for a 1992 rinker 186 with a 4.3 Yamaha. I'd like SS, it currently has no prop, I'm looking for just a good all around prop. I've had so many sizes and pitch suggestions and have no idea.

Given you don’t have a prop I assume you just bought the boat?

Personally Try a 19” 3 blade aluminum to rough in where your wot rpms will land. You can move up to stainless from there and tweak pitch

You may be aware that Yamaha only sold sterndrives for a handful of years , parts are hard to come by

 

[cyclops222]

How did the test ride go ?

 

[bajaman123]

Wow...a Yamaha sterndrive post...haven't seen one for years. Having had a Yamaha Hydra Drive powered boat (big block Chevy), I became a fan of these sterndrives over the years. If my memory is correct, that outdrive has a 1.65:1 ratio, and the engine was a 2 barrel making 190 hp. As noted above, a 19" pitch prop is a good starting place; if you are fortunate enough to have a friendly marina close that has a "try before you buy", you could certainly try a 19" Mirage for example...that, in my humble opinion, would be at the extreme end of what that engine will spin. 4200 - 4600 rpm was the WOT operating range...I believe...so you want to find something that will allow the engine to run in that range.

On a related note, is Capt. Ken still around? He was the go-to guy for these sterndrives...

 

[whydoihateboats]

The prop question is mute point. Long story short, got the boat cheap because it needs a total interior rebuild, now after getting it running and in the water it's got cracked manifolds and milky oil. It sucks because the hull is in great shape.

 

[Scott06]

The prop question is moot point. Long story short, got the boat cheap because it needs a total interior rebuild, now after getting it running and in the water it's got cracked manifolds and milky oil. It sucks because the hull is in great shape.

Check stringers and transom for rot By drilling holes. I believe keyhole is same as merc and could swap drivetrain out of a merc 4.3 pretty easily Of you are handy.

problem is interior work isn’t cheap unless you can do it yourself

 

[bajaman123]

Dang...that sucks to hear about the bad manifolds. Still might be worth fixing...