Single or dual exhaust???

[Smitty65534]

I've got a 1989 Force 85 hp, Model #853F9E, S/N 016132 and need to order a spare prop. Can anyone point me to a source that will identify which prop it takes (by model #) or which type exhaust it has?

I think it is a single exhaust but can't be sure, and evidently, the props are different. The boat is a couple hours away and I don't know if I could tell by looking anyway.

Thanx - Smitty

 

[john from md]

Re: Single or dual exhaust???

It is really easy to tell if you have a through the prop exhast. The area around the center is open and you have four or five supports going from the inner hub to the outer hub. On an engine that only uses the snout for exhaust, the hub of the prop will be solid and you can't see through it.

John

 

[Smitty65534]

Re: Single or dual exhaust???

Thanks John - I know it has an exhaust outlet above the prop and am not sure about through the prop. I don't think it does. I was just trying to save a 4 hour round trip to the lake to check it out.

Appreciate the input.

Thanx - Smitty

 

[jerryjerry05]

Re: Single or dual exhaust???

89's have an open prop.The exhaust goes thru a snout and out the back of the mid section.
As far as size your prop has numbers stamped into them.You will need to go look and see what they are.J

 

[NYBo]

Re: Single or dual exhaust???

I have an '88 and an '87, both 85 HP. The prop on the '88 is a through-hub exhaust style, and the '87 has the closed style. However, the lower units are the same design- single exhaust through the exhaust snout, not the prop hub. Some prop finder applications say they are both through-prop exhaust, some say not. Go figure.

 

[Smitty65534]

Re: Single or dual exhaust???

Bob,
What I THINK I am hearing is that there is probably only one prop that will fit an '89. I don't remember ever seeing exhaust/water out the prop hub while running on muffs. The prop finders seem to indicate that I can only order a prop for a "dual exhaust."

Thanx - Smitty

 

[NYBo]

Re: Single or dual exhaust???

Yep, I've virtually positive we have single exhaust lower units, but most prop finder apps say they are dual exhaust. But an open hub prop will work just fine as long as the hub diameter, shaft diameter and spline count, and hub length are right. The closed hub props I have use a spacer between the prop and the nut; the open hub props don't use a spacer but are the same overall length as the close hub + spacer.

 

[Smitty65534]

Re: Single or dual exhaust???

Bob,

Thanks a bunch. I think I'm going to order a "Pirana" composite and hope for the best. Appreciate the time. Have a good evening.

Thanx - Smitty