85 Force 125 cooling question

[Racer]

Ok, my 85 Force 125 is running pretty well for the most part.

Now and then my heat alarm will go off. Its usually when we do stuff like waterskiing and I have the boat in gear and just at idle circling around to pick up a skiier or whatever. If the alarm sounds and I put it into fast neutral, it will stop within a couple of seconds.

It seems to me that just not enough water is flowing when the engine is at a slow idle. Idling in neutral seems to be at a higher rpm and I have not noticed any problems.

I did check the thermostat and it seems to open up the whole way when I put it in hot water.

I am guessing I need a new impeller. My question is how difficult is it to replace that? Is it just a matter of dropping the lower unit and putting in a new one or is there a bunch of stuff that will need to be unhooked first. Also any special tools required? Will the prop need to be removed? What seals if any will need to be replaced before bolting it back together?

I have plenty of experience with car engines, but very little with an outboard.

Thanks

Jeff

 

[Scaaty]

Re: 85 Force 125 cooling question

I am guessing I need a new impeller

me too..not hard but YOU MUST HAVE A MANUAL...AND FOLLOW IT..

 

[newbie4life]

Re: 85 Force 125 cooling question

Replacing the impeller is not that difficult at all.

There are a few things that you do need to do, however. I'd recommend getting a manual, too. I purchased one online, and can look at it, print off pages, etc. It was much faster (and cheaper) than buying the big book. If you want the website, I'll post it up.

 

[Scaaty]

Re: 85 Force 125 cooling question

Thing is, the manual will explain how to set the shift right, and for Gods sake DO NOT REMOVE THAT CENTER PHILLIPS HEAD SCREW ON THE GEARCASE!!!!

 

[1fullforce]

Re: 85 Force 125 cooling question

Ok, my 85 Force 125 is running pretty well for the most part.

Now and then my heat alarm will go off. Its usually when we do stuff like waterskiing and I have the boat in gear and just at idle circling around to pick up a skiier or whatever. If the alarm sounds and I put it into fast neutral, it will stop within a couple of seconds.

It seems to me that just not enough water is flowing when the engine is at a slow idle. Idling in neutral seems to be at a higher rpm and I have not noticed any problems.

I did check the thermostat and it seems to open up the whole way when I put it in hot water.

I am guessing I need a new impeller. My question is how difficult is it to replace that? Is it just a matter of dropping the lower unit and putting in a new one or is there a bunch of stuff that will need to be unhooked first. Also any special tools required? Will the prop need to be removed? What seals if any will need to be replaced before bolting it back together?

I have plenty of experience with car engines, but very little with an outboard.

Thanks

Jeff

HI RACER , I CHANGED MY IMPELLER ABOUT A MONTH AGO AND IT WAS NOT DIFFICULT AT ALL ,DRAIN LOWER UNIT, BEFORE DROPPING LOWER UNIT SET LEVER IN FORWARD OR REVERSE, LOOK FOR THE LOWER UNIT HIDDEN BOLT INSIDE THE EXHAUST SNOUT, ***BE CAREFUL NOT TO BREAK THE LOWER UNIT`S BOLTS*** OR WATER PUMP HOUSING`S . WHEN INSTALLING NEW IMPELLER PUT A LITTLE GREASE ON THE PUMP HOUSING(WHERE IMPELLER RIDES)

 

[Racer]

Re: 85 Force 125 cooling question

Next question, where to find one?

I did not see a listing for my engine on iboats.com

I found a place in Canada that has them, but I would rather deal with something a little closer. I checked my local bayliner dealer and they do not stock them.

I am in North Carolina

 

[baxtr]

Re: 85 Force 125 cooling question

http://www.outboardparts.com/chrysler/mall/forceimpellers.htm

 

[1fullforce]

Re: 85 Force 125 cooling question

hi racer , i am from north carolina too ,, oxford nc north of durham , where are u located?

 

[Racer]

Re: 85 Force 125 cooling question

Mooresville. Race City USA

Not that far away actually.

You wanna come over and drink some beer and help put in an impeller? hahaha.

 

[baxtr]

Re: 85 Force 125 cooling question

Mooresville. Race City USA

Not that far away actually.

You wanna come over and drink some beer and help put in an impeller? hahaha.

BEEEEEEEEEEEEEER I am looking up mapquest right now, may take awhile from WI LOL

 

[Racer]

Re: 85 Force 125 cooling question

Ok, I got it apart without too much trouble. Now just a few questions.

The impeller was definately worn.

I noticed inside the housing, it has some pitting. It is definately not completely smooth. There is part of it smooth and part of it is definately pitted. (Its aluminum)

Do you think it should be replaced? I am guessing that is going to be a little harder to find.

Also, the driveshaft looks to be rusted up some. Is this normal? Should there be any kind of gasket or sealant between the 2 halves? I mean it looks like there is really nothing stopping that part from having water get in.

Should there be any kind of a thread sealant on the 7 bolts holding the lower unit in place? In a small block chevy we always put a sealant on the bolts because they go into the water jacket. The bolts I pulled out definately had a little corrosion that is why I ask, or should I just add some anti-seize to the threads and put them back in.

I think that is all the questions for now.

Thanks

 

[Frank Acampora]

Re: 85 Force 125 cooling question

You don't need a gasket between the two halves. I like to coat my screws with anti-seize --really gop them up. --Especially the water pump screws, so I can get them out next time. Some people swear by Vaseline Petroleum Jelly and others use black rtv silicone. Even though the drive shaft is stainless, because it is in the exhaust path it tends to pit and rust a little. I use a skotch brite pad to remove the rust then coat the shaft with hi temp anti-seize--Rub it in good with a paper towel. The pitted housing will work, depending on how bad the pitting is, but eventually you will need to replace it.

Just so you know: The impeller acts like a positive displacement pump by rubbing against the housing at low speeds. At higer speeds, water pressure forces the vanes away from the pump wall and it acts like a centrifugal pump. That is why mild pitting will not affect it much.

 

[Racer]

Re: 85 Force 125 cooling question

Nice! I will see if I can pop that back in tomorrow and see how it goes. I guess worst case scenario I have to pull it apart and replace the whole housing.

The only time I had trouble was when it was in gear just off idle when the rpm's were low, like swinging around to pick up a skiier or something. No other time did it give any kind of trouble.

This message board has been a wealth of information and I appreciate everyones input.

Maybe I will put in a tell-tale like was discussed in another thread and I can kind of keep an eye on the output.

 

[tds1774]

Re: 85 Force 125 cooling question

I just bought an 86 bayliner with a force 125. btw my wife is from mooresville And I worked @ marshall and in oxford @ certainteed. is it hard to change the impeller? mine just spits a little water out I was tthinking it should be a steady stream. also , know anything about carbs? the bottom carb is over flowing a little.