PROP SELECTION HELP

[Wonbigfish]

I recently had to replace my 90 hp force. I found a 1997 90 hp with great compression. Mounted it up on a 16 1/2 Palm Beach. Swapped out carbs, new water impeller and ran great. The prop seemed perfect and it was for a year. Decided to replace the aluminum prop with stainless of equal performance. Couldn't get prop off lower unit to find size numbers. Had to cut, beat & cuss it off. Only to find nimbers missing or corroded away. I read several web site sizing sugestions and purchased a used Ballistic 13 1/2 x 17 stainless prop. It just doesn,t have the same hole shot nor speed. I don't have a tach but I think it's running at higher RPMs. I fish the flats of Mosquito Lagoon. It requires a quick jump on plane & enough speed to do the skippy through flats.

 

[jerryjerry05]

You have the serial #s Possible the Mercury people can tell what prop was sold with the motor? Probably not but maybe?
What did it come off of? Again the boat manufacturer might have the info??
Go to Michigan propeller Tell them what you have, motor, boat, load and anything you can think of??
The operating range for that motor I believe is 52-5500rpm's

 

[Wonbigfish]

Do you think that info is still avail? I have looked several prop selection guides. They all seem to work off rpm & speed. Is there a wire at consol end of harness for a tach? I have a Garmen gps to get speed. I am just tired of paying extra for guessing?
Thanks

 

[MickLovin]

Yes there is a wire for your tach refer to your model's wiring diagram

 

[Frank Acampora]

It really depends upon how heavy your Palm Beach is and how many passengers you will carry. For example MOST 17 foot Bayliner bowriders I have seen with a Force 90 came from the Factory with a 13 X 15 prop. Dropping down a foot in size, a 17 pitch might be a good choice but not if you intend to carry a heavy load. Then, a 15 pitch would probably be better

 

[jerryjerry05]

Most 17 Bayliner's came with a 17 or a 19.
The 15p was used on HEAVY boats or pontoons. .
The 19 came with a 125 or 120 and a 19p
My boat is a 21 and has twin 85's
It came with 17p The 17p is actually enough to get it on plane with 1 motor.
Depending on load.
The 15 put's it up a lot faster.
They made my boat with a single 125/120,21ft by 8ft. and it came with a 15p
Your motor came with a tach lead.
Could be taped back somewhere.
They sell an item called a Tiny Tach.
Will give you the info you need.
They also sell the tach for your motor.
I believe it's a 12 pole tach.