Can't find prop size/pitch

[EZDude]

Hello to all,

I am trying to replace my recently damaged prop. As such, I am trying to find the prop size for the prop installed on my boat.

I have a 1990 Glastron Sierra 175 with a new 4.3LX Mercruiser (4 bbl w/ Vortex heads) and an Alpha One sterndrive. I believe the engine is 220Hp based on conversations with the dealer I purchased it from. It is a new 2005 engine.

I have read that you can find the prop size stamped on the prop. However, it hasn't been so simple for me.

This is what is stamped on the side of the prop:

"48 781 22 A40 21P" (It is hard to see the "A" so I am not sure if it is an "A" or a "4"

This is what is stamped on the inside of the prop:

"48-781-22 21"

Now, I am assuming the pitch is 21, based on the 21P, but not exactly sure. Also, I can't determine the diameter based on this information. I do know that this is not the original prop as the original owner stated that it had been replaced.

It is much appreciated if anyone can help me with this.

Thanks in advance.

 

[EZDude]

Re: Can't find prop size/pitch

I took this prop into a local repair parts distributor. The clerk was stumped also.

I am pretty sure that I want to stick with a 21P prop. I just need to make sure I get the right diameter.

If I have a Mercury Alpha One sterndrive, then any prop designed to fit this unit will work, correct? I just need to choose the desired pitch, correct?

Thanks again.

 

[Tail_Gunner]

Re: Can't find prop size/pitch

Yes use the prop selector here and any prop should work...On inboards dia really cant be messed with...you see your outddrive has a 4.5 inch hub and you need to stay with that or you will create a disturbance in waterflow to the prop...not good at all...Besides mfg take dia into account when building the pitch rake etc...Solas stilleto great props and very cost effective very