Fisher Freedom 240 DLX prop issue

[moparone]

Sorry, must have hit the wrong button. We have a 1990 Fisher, 24'x8' two log pontoon, it weighs about 2400 loaded. It has a 1990 90 HP mercury with a 13p prop. WOT gives us about 3200 rpm and about 20.5 mph. I've called Tracker and got no help. Just received info on TAP Fins, nice but pricey. Does this seem right? Thanks

 

[etracer68]

Re: Fisher Freedom 240 DLX prop issue

First, Im not sure what "Tap Fins" are. I would say if WOT only gives you 3200 rpm, with a 13 pitch, you may have other problems. Are you sure your tach is reading right? Is the motor running good. Something just isnt right here.

 

[moparone]

Re: Fisher Freedom 240 DLX prop issue

First, Im not sure what "Tap Fins" are. I would say if WOT only gives you 3200 rpm, with a 13 pitch, you may have other problems. Are you sure your tach is reading right? Is the motor running good. Something just isnt right here.

I think It's right, was thinking we needed to change the prop to get the rpms up, this room drags a lot of water, the TAP Fins are pcs of aluminium that weld or epoxy to the logs to get more lift and cut out the spray of water underneath the deck as well as outside. They have a web site, would love to have them but at 1300.00$, not rite now. Do you think the prop is an issue, it will rev way past 3200 while not in gear....

 

[etracer68]

Re: Fisher Freedom 240 DLX prop issue

General rule of thumb is 200rpm gain with one inch of pitch decrese. I think you motor should be running at least 5500 rpm @ WOT. I think if you do the math, you would be down to much in pitch. Something still is not right with your rpm.

 

[steelespike]

Re: Fisher Freedom 240 DLX prop issue

I think your speed is slow but within reason. Its not possible to go 20 with a 13 at 3200 rpm. especially with a pontoon. was your speed by gps?I think the tach is not correct, reading low.
13" @ 3200 with 25% slip (my guess) produces about 13 mph.
A 13" at 5500 25% slip produces 22 mph. 25% is a guess on my part.Slip is high on a pontoon.
I think you would be better off with a water glide ? not sure of the name but its an
after market 3rd log.It gives more flotation and planing surface boat gets up almost like a runabout.
Do a search on You tube. I stumbled on a video the other day looking for something else.
Sometimes if you operate the tach switch a few times it will clean the contacts and work better.

 

[moparone]

Re: Fisher Freedom 240 DLX prop issue

I see on a few threads about a switch on the tach, ill check that, if my tach comes around, then what? Have you looked at the TAP Fins???

 

[steelespike]

Re: Fisher Freedom 240 DLX prop issue

I added more to my previous post.