86 Force 85 HP Impeller Change

[dorelse]

So...following the instructions from the sticky at the top of this forum. I went ahead and removed the outdrive to check and change the impeller. I can turn a wrench, but that's about it. I followed the instructions, and removed it without issue. Like everyone says, its pretty easy.

I've taken some pictures, but do have a couple questions. Mainly, I didn't have any gaskets anywhere, none on the impeller housing, or where the outdrive seals to the middle leg section. Should there have been?

Also, when I put back the gear lube, my Mercury brand bottle pump doesn't fit, its too big, what size do I need to attach the to the lower unit? And, how much do I need?

Finally, are the collar and rubber seal on the top of the drive shaft in the correct orientation? (Last pict.)

Anyway, here's some picts:

 

[Frank Acampora]

Re: 86 Force 85 HP Impeller Change

There is only one gasket below the stainless plate that the impeller rides on. It is good procedure to replace it but it is not absolutely necessary if there is little corrosion--if that's the case, it is likely that the torpedo shaped plate will be ok.

I can't tell if the steel collar has the groove up but it looks like the rubber seal is upside-down. The flat or squareish portion fits in the groove of the collar and the tapered end matches the taper in the bottom of the crankshaft.

I really don't remember how much oil goes in the lower unit because I pump mine from a bulk container and just pump until full. I think it will be somewhere between 24 and 32 ounces. Best to buy 2 quarts to be safe though.

Sears and Pep Boys sell a pump that has a nozzle that will fit. Or, no need to discard your existing pump. You can get a plastic tube fitting for 3/8 tubing. The fill hole is 3/8 threaded and the tapered 3/8 fitting should fit. If not, go down the 5/16 inch.

 

[dorelse]

Re: 86 Force 85 HP Impeller Change

I can't tell if the steel collar has the groove up but it looks like the rubber seal is upside-down. The flat or squareish portion fits in the groove of the collar and the tapered end matches the taper in the bottom of the crankshaft.

I have the collar with the groove up, and the thin narrow portion in the groove in the picture. I have since flipped the rubber seal so that the 'thick' portion now sits in the groove of the collar, it seems like a perfect fit, with the thinner portion ready to slide up into the crankshaft.

I've attached 2 pictures. The first one, is how I think it should go, the groove in the steel collar matching up to the thick portion of the rubber seal. In my first post, last picture, I have it like the second picture. The thick portion up, with the thinner section sitting in the groove in the collar.

Let me know, I was thinking the first one, that I had them reversed initially.

I should also mention that there's little corrosion, the gear oil came out perfect, no frothing or milkiness of any kind. I wasn't planning on even touching that seal, as I didn't think the impeller change required it. This is a freshwater only boat, and looks to have seen little use.

I did check compression on all 3 cylinders and they came out at 135 on all 3...so I think I'm good.

I'm pretty new to Force engines, and I couldn't tell if the way the motor was spitting water was ok or not. The engine hadn't run in 2 years, and its new to me, so it was more just to explore and check it out to be safe.

I thermostat though looks original, and did have some chalkiness to it, so I'm going to replace that tomorrow. (The engine heated up in about 30 seconds and the high temp alarm sounded, so I thought impeller first, then thermostat.) It is spitting water, hot water...which is why I thought the impeller wasn't working at full capacity.)

It actually looks to me like the fill spot is 1/4 in., I measure the thread width on the plug, and its 1/4 in...is that possible? 5/16 in is too large I believe.

Thank you very much for your help, and posting your instructions.

 

[dorelse]

Re: 86 Force 85 HP Impeller Change

Success! Put the impeller back in. Tightened everything up (with Anti-Seize) and it slid back into position without issue. (Well, ok, a little jostling to get the crank to mate up correctly.)

I love the trick of using a little liquid dish soap. When I fired up the motor, I had a little dish soap foam...just a very little...and knew the impeller was working.

In my first post I mentioned that the high heat temp alarm was going off, so I pulled off the thermostat today, and warmed it up in water on the stove. It opened right up.

I'm hopeful that the crud that came off it has allowed it to work properly again as a new one won't be in until Friday.

BTW...they said a thermostat gasket isn't available anymore? So I just used engine (automotive) water pump gasket sealer and made my own as a temporary fix. Anything wrong with that approach? Its holding just fine, and my tell-tale water (well, the spit water) is warm, but not hot to the touch, and I can hold my hand on the engine easily, so I know its working.

 

[mrdoorguy]

Re: 86 Force 85 HP Impeller Change

I Just Bought A Boat With An 85 Hp Force Outboard. The Water Is Not Coming Out Of The Power Flow Ports. Not Good Right. Do I Need To Change The Impeller And How Do I Do It. Im New To This Site Also, What Is A Sticky And Wher Is It???

 

[Dave K.]

Re: 86 Force 85 HP Impeller Change

First: welcome to the site.
Next: the sticky is one of the first posts saying "impeller change"
Last: yes, change your impeller (anyway). But, some Force motors don't like muffs (if your using muffs) some do, mine doesn't so I use a BIG aluminum wash bucket & submerge the entire LU (a bit more of a Pain in the A**, but sure beats changing head gasgets)

 

[john from md]

Re: 86 Force 85 HP Impeller Change

If you used the blue or red permatex gasket maker, they will hold up fine. As to the muffs, look for he type that uses a hose on each side. They pump more water and the bigger Force engines like that.

Mr Door guy,

Start another thread and give us some additional info. Like how long has it been since it was run last, does it have a new water pump, is it saltwater or fresh etc.

The more that you tell us, the easier it is to help you out.

John

 

[mrdoorguy]

Re: 86 Force 85 HP Impeller Change

Ok I Don't Know To Much About The Boat, But I Posted A New Post And I Have Some Other Questions. Its Called 85 Hp Force Hard Starting After Warmup. Once Again Any Advice And Replies Would Be Greatly Appreciated!!! Thank You