Prop Advice

[PCholidayDLX]

Hi, had a discussion with the tech that fixed my fuel issue recently and one of the topics was the prop I'm using.

I inherited this boat from my brother, so its kinda new to me.

Anyway, the prop that is on there now is the "spare" rubber/plastic type. It was suggested I change to a 3.75 pitch 15" aluminum prop for better performance.

The boat is a Princecraft 16' Aluminum hull (pic in my avatar) with a Mercury Big Foot 50hp 4 stroke EFI outboard.

Does this recommendation sound right to you all?

Thanks

 

[craze1cars]

Re: Prop Advice

No. You must have misunderstood the numbers he threw out at you.

The 3.75 part makes no sense whatsoever. 3.75 is not a pitch that is available in outboard boat propellers. Nor is a 3.75 diameter.

15" however, is a common pitch measurement, and a common diameter measurement as well. Which dimension is the 15" referring to?

Have absolutely no idea what 3.75 could be referring to...unless it's maybe gearcase housing diameter??

What is the current pitch of the composite prop you have installed now? And what is you top speed and max RPM with this prop? Based on that info, we might be able to get you in the ballpark of what to buy.

Even a BETTER alternative, is to go back to this tech and just ask him to hand you the prop he is recommending for you boat, with
the understanding that you can test-drive it and exchange it for a different one if your RPMS are not correct and you return it undamaged. If he's willing to do this, there is no better way to buy a prop...

 

[PCholidayDLX]

Re: Prop Advice

Yeah, I think I mixed the numbers up - 13.75 dia and 15" pitch...

Thing is I don't have a tach or speedo on the boat and he'd be ordering the prop so I was tryin to get a close a possible initially...without having the cost of him coming to the lake and getting the rpms/mph.

Boats nuthin special (see avatar pic) 2000 16' princecraft aluminum hull - was just looking to improve upgrade composite prop to aluminum to get what I
can outta the 50hp motor...

Does that make sense?
Do you thing the prop upgrade will make enough of a difference?

Really appreciate the feedback as this is all new to me.....

 

[Maclin]

Re: Prop Advice

That is not really an upgrade as the prop on there now is for minimum load and speed, like limping home to the ramp. That 15 pitch prop is in the ballpark, might be a little too much for a 50hp on a 16footer, but being aluminum the boat may move out ok. I think on a 15 foot trihull fiberglas boat the 15 would be too high. The best thing to do is buy from a prop shop or dealer that lets you swap around some. It may cost a little more but the return factor is worth it unless you know exactly what will work already.

 

[craze1cars]

Re: Prop Advice

Without a functioning tach, any prop is a guess....

13.75" dia x 15" pitch makes much more sense...that's a valid prop size and it may be a good suggestion. And it may not. It all depends on what RPM it runs when installed on the boat.