1989 85hp Force

[michael cain]

new to boating and have purchased a 24' pontoon w/ a 1989 85hp Force o/b. Needs a new prop. Any suggestions as to the best pitch? Also, the previous owner said he put 16 oz. of oil to 5 gal. of fuel. Seems a little high to me. Anyone know the recommended mixture?

 

[12Footer]

Re: 1989 85hp Force

I can't help much with the pitch, besides this link, or or this one because the only real way to select the best prop is thru trial and that can get crazy... But the oil/fuel ratio is 50:1. 16oz to 5-US gals is a bit oily. No probs with that, except the added fouling/carbon buildup problems. 16oz to 6-US gals is closer to normal.

 

[MWBROWN]

Re: 1989 85hp Force

My guess would be a 15 or 17 pitch, 13" diameter. Based on the size and weight of the craft.

You can get used ones on EBAY pretty cheap sometimes, and if it is not perfect you can use for a backup prop.

You should run 5200 to 5500 rpm at wide open throttle, with a normal load.

Hope this helps, and good luck.

Mike

 

[steelespike]

Re: 1989 85hp Force

If your prop isn't too bad you can have it repaired by a prop shop a lot less than new.Also the size may be stamped on your prop or numbers a prop shop could look up.
I'm thinking no more than a 12 inch pitch possibly a 13.A 115 Etec on a 22 Crest uses a 13 inch at 5,630 rpm and 29 mph(screaming for a pontoon).

 

[Frank Acampora]

Re: 1989 85hp Force

As I remember from looking at catalogs, you don't have much choice in props for that engine---13 diam X 15, 17, 19, 21 pitch. That's it. Go with a 15 pitch unless by some stroke of luck you can find a 13 pitch. You might be able to find a small gearcase (4 1/4 inch--90 hp) Merc prop to fit.--same splines on shaft. Them you might have more choice.

 

[jimmystire]

Re: 1989 85hp Force

I just brought the same package and i can not find a 13" prop that will fit besides the 19" and my lake is very rocky (lond pond lakeville ma) so i know I will need props thanks jimmy good luck michael if I find anythig I'll post it !!!

 

[MWBROWN]

Re: 1989 85hp Force

There are 13 dia x 15 pitch Force Props on EBAY all the time. Not today though. Keep looking.

I know a place called Port City Props that may have some rebuilt ones. They are on line, you can figure out its address. Not allowed to put it in here.

IBOATS sells new ones

I bought a 13 x 15 used for 30 bucks plus shipping.