Found a New Anchor, Now Time for a new Prop

[edsblack81]

I had just pulled my boat off the trailer yesterday and started having problems getting in to gear. I looked and I had an anchor wrapped around my prop and now my prop is beat up pretty badly. I am new to boating this year and would like help selecting a new prop.

I was considering a new prop pitch before messing up my prop yesterday since I am not hitting the appropriate WOT RPM, but now I don't have a choice.

Here are the specs for what I have now. I would like a few more MPH if possible but ultimately just want my WOT RPM where they should be.


1) Not hitting the proper WOT RPM and would like a few more MPH.
2) I have a Mecury Propeller installed currently. It is stamped with the following model number - 48 16440a45 16p.
3) The current diameter is 16 and the pitch is also 16.
4) My current WOT RPM with an average load is 3,900-4,000. It is recomended to be 4,400 to 4,800. (This was before the anchor chewed up my prop.)
5) I have a Mercury 3.0L with an Alpha One. It is a 2002 with 135HP.
6) I have a 2002 27' Sun Tracker Party Barge that weighs 2,400 lbs. (Yes, a pontoon with an I/O.)

I am up in the air between a 14 and 15 pitch. Before I found the anchor yesterday my prop had a few small nicks and dings but nothing major. I don't know if those nicks and dings would have lowered my WOT enough that I should only step down by one pitch or if I should step down by two pitches to pick up the full 800 RPMS I am missing at WOT.

Thanks for any advice.

 

[jimmbo]

Re: Found a New Anchor, Now Time for a new Prop

Your current rpm is 3900-4000 and the recommended is 4400-4800. Since the usual rule of thumb is 400rpm for every 2 inches you need to drop 4 inches. Now, I might be wrong but, I doubt very much you can put a 16 inch Dia prop on an Alpha One drive. Getting more speed out of it? That is a heavy barge and you have a small motor? Does it get up on Plane? If it does, how fast does it go?

 

[edsblack81]

Re: Found a New Anchor, Now Time for a new Prop

Thanks for the input jimmbo.

I realized that I forgot to include my current top speed in my original post. The current top speed is 23 MPH. As far as getting on plane. I am not entirely sure. In smooth water, I feel like it is gliding on top of the water, but I don't know if it actually is or not.

You can put a 16 inch diameter prop on the Alpha One because that is what is on there right now (I can't say for sure if it should be on there but it was on there when I bought the boat). The Mercury Prop Suggestion tool also recommends a 16 inch prop for my application.

This made me think of a follow up question for everyone, has anyone bought a prop based on the Mercury Prop Selector suggestion? and how did it work out for them?

 

[jimmbo]

Re: Found a New Anchor, Now Time for a new Prop

I didn't think an Alpha One could fit a 16 in dia. I was Wrrrrrrrooo, mistaken

 

[steelespike]

Re: Found a New Anchor, Now Time for a new Prop

There is something about the 16" pitch a 16 X 16 seems common.It must be some sort of converging point.
I think you should try a 13" pitch Being an odd number I think you will find more choices both in technology and price.
If it turns out to be a little light you can watch the rpm and still use it.A 13 should add 400 to 600 rpm.Will add some pep and will push a load better.Actual results on a pontoon are really hard to predict Slip will be really high and any increase in speed slight
if any. Your present slip is 24% respectable for a pontoon.
with some luck a 13" may produce the same or a little better speed.
But keep in mind a pontoon doesn't add speed very easily.