Searching for new prop

[BrianN]

I am in the market for a new prop. It looks like mine was damaged before I bought it, and repaired. I had just noticed that one of the blades in cracked, and would just like to have it replaced.
We have a 16' Malibu with a 120hp Force we use just for lake fishing. We only have my wife and myself in the boat. Although, when we first bought it, we had two passengers and the boat got up on plane no problem and ran great.
The boat is around 1800lbs, probably 2200lbs fully loaded for a day out on the lake. WOT we get 42mph at 5200rpm.
So, my question is, since every thing is working good, I plan on keeping the same prop, but, should I go stainless or aluminum. And, should I go three blade or four?

Thanks for your help.

 

[SkiDad]

your numbers look spot on. If you go stainless in same brand you will probably loose 200 rpm - that has been my experience with a similar engine to yours.

If you are running something like a Mercury black max prop i believe they have a stainless version that you get in 1" less pitch.

​

 

[Sea Rider]

What's the max wot rpm range for that motor ?

Happy Boating

 

[BrianN]

your numbers look spot on. If you go stainless in same brand you will probably loose 200 rpm - that has been my experience with a similar engine to yours.

If you are running something like a Mercury black max prop i believe they have a stainless version that you get in 1" less pitch.

​

Thanks SkiDad. I will just stay with what I have. Three blade aluminum.

 

[BrianN]

What's the max wot rpm range for that motor ?

Happy Boating

My WOT is 42 mph @ 5200rpm.

 

[SkiDad]

i believe that motor is supposed to be in the range of 4750-5250 rpm at WOT

 

[Sea Rider]

Yep, check factory min-max wot rpm range. If 5250 and achieving 5200 rpm full hammer down as "currently loaded", you are already at wot peak. If combo runs satisfactorily stay with current prop, 50 wot rpm difference is nothing.

Happy Boating

 

[BrianN]

Excellent, good to hear. Thank you for your input.