prop on my 85 horse force

[DTVDRAGON]

helloo all! first post at this great site I found, Iam a new boat owner, I bought a 89 bayliner capri (17.5 foot) with a 1989 force 85 horse motor.
the motor has been all rebuilt. anyways the seller gave me two extra props with it, one of the extras is stamped 13 1/4 x 17. the one on my motor has been rebulit and I can just see a number 15 stamped on it. but it is physically smaller so I know it isnt a 13 1/4, it must be a 12 1/4 prop x 15 pitch. Iam debateing wich prop should I keep on my motor? I cannot take out to the lake to try out each as we are done with holidays for this year, so Iam hopeing one of you gurus can enlighten me on wich prop will give me the best performance , any help will be greatly appreciated thanx

 

[bentle]

Re: prop on my 85 horse force

15 pitch for better shot out of hole. 17 will give lower rpms but while give better mph out on plane. 17 is to much prop for your motor coming out of the hole. I have a 120 hp force outboard with a 17 pitch and cruising speed is great but out of hole
Is slow. Changing to a 15 pitch asap. You might even want to go with a 13 on yours if you plan on pulling tubes or any skiing.

 

[DTVDRAGON]

Re: prop on my 85 horse force

Thanx for the reply,the people I bought the boat from did pull a tube, we will be as well so I guess I will leave the 15 pitch prop on, prolly why its on there in first place, this 15 pitch that is on there isnt 13 1/4 like the 17 pitch spare I have,so Iam guessing its a 12 1/4, is that a correct asumption?

 

[jerryjerry05]

Re: prop on my 85 horse force

The ONLY way to get he boat/motor set up right is to go for a ride.
You have a tach? WE need to find out the rpm's at wot.
Boat load will affect performance.
Say you go out with a dog and a BIG cooler full of beer and 2 kids and 4 fat girls.Then your performance will not be right.
A normal load 1-2 adults 1-2 kids dog and cooler and 1/2 tank of gas.Then go for a ride.
If your running 5500rpm's at wot then your prop is the right one.
Too low on the rpm's and you need to go down in pitch too high then up in pitch.
If you run a 17p and the rpms are 5000.Your economy will suffer.So get the rpm's in the right range and you will be OK.
Make sure the motors running right too,The comp and spark is good and the carbs set.It all plays in to the best you can do.J

 

[bentle]

Re: prop on my 85 horse force

Yep jerry said it best. Stick with the 15 pitch for now. Get her out on the water and see what the tach reads at wot. 5 grand will be ok but crappy on fuel. You will want to see 5300-5500 for best performance. You may want to get a smaller pitched prop for out of the hole. No smaller than a 13 pitch and with that said watch your tach. Don't want to go over 5500 rpms or then you will have even bigger problems. Keep the 17 in the boat for a spare. Never know when you may need it.

 

[DTVDRAGON]

Re: prop on my 85 horse force

ok thanx guys, guess I will need to wait till next year to test this all out. I just bought the boat and it is all in excellent condition, gave me $2000.00 in invoices for just the motor alone...only thing i need is a front bow cover,,,this seems like an excellent forum and I know I will become a regular here.....