I have a 1986 Mariner 150 Magnum. The current prop does not have any markings on it of any kind. It is bent and I took it to a prop guy and he couldn't find markings either. I would like to buy a new prop but don't know what size to buy. I would like to keep the same size. It jumped out of the hole fast and ran about 64 mph WOT. Does anybody, by chance, know what size props came on that motor originally? This is the original prop.

It probably is a 19 or 21 pitch.  The boat size and weight will make a difference in which prop works best.  A good prop person should be able to tell what it is.

 

The option that I choose is test props on the water for performance.

Ok. Thanks. 

I had that same motor on a Ranger 363 ( about the same lenght as your boat) and use a Mercury Lazer prop in 23 P.

Factory aluminum props may not have identification but should have serial number stamped into the prop. Prop repair shop has tools to measure the prop pitch, rake and cup. Suggest going to a SST prop.

Tom

12 minutes ago, WRB said:

Factory aluminum props may not have identification but should have serial number stamped into the prop. Prop repair shop has tools to measure the prop pitch, rake and cup. Suggest going to a SST prop.

Tom

Yeah, Tom, we couldn't find a number of letter of any kind on the prop. The prop guy and I both went over it multiple times and couldn't find anything outside anywhere or inside the hub center area. Pretty crazy. 

3 blade aluminum Mariner was met for export market, mostly Canada. Look at the Mercury 6 inline cylinder 150 hp for recommended prop, SST would be a Lazer series.

Tom

Thanks Tom.

Like Tom said a good prop shop has the tools to measure yours.