'87 Force 85hp not circulating water

[bet123]

My '87 Force 85hp motor is not circulating water. I changed the impeller and it made no differance. I thought maybe there was a blockage in the system. So while the motor was running I ran water into the inlet ports on the lower unit. No water circulated it just came out of the mating surface bewteen the lower unit and motor housing. I removed the lower unit and the thermstat then ran water from a hose into the openings in the thermstat housing, one at a time.
Each time water flowed out of the water tube going to the water pump and out of the exhaust port just above the propeller, but no water came out of the two ports just below the powerhead. Then I ran the water into the two ports below the powerhead and it came out of the same two places, the tube and the exhaust port.
Any ideas ?

 

[Netjunky]

Re: '87 Force 85hp not circulating water

My '87 Force 85hp motor is not circulating water. I changed the impeller and it made no differance. I thought maybe there was a blockage in the system. So while the motor was running I ran water into the inlet ports on the lower unit. No water circulated it just came out of the mating surface bewteen the lower unit and motor housing. I removed the lower unit and the thermstat then ran water from a hose into the openings in the thermstat housing, one at a time.
Each time water flowed out of the water tube going to the water pump and out of the exhaust port just above the propeller, but no water came out of the two ports just below the powerhead. Then I ran the water into the two ports below the powerhead and it came out of the same two places, the tube and the exhaust port.
Any ideas ?

So you ran the motor without muffs or not in a bucket for this test? If so that new impeller that you installed will be toast. I just takes 20 seconds of running to wreck it. It takes a good water flow from a hose and muffs attached to the lower end to produce water circulation.

http://www.youtube.com/watch?v=B84JONVw5HU

Note: Don't put the motor in gear like this guy while on muffs...

 

[chitownborn]

Re: '87 Force 85hp not circulating water

check to make sure the keyway for the impeller didnt slip or you forgot to put it in

 

[bet123]

Re: '87 Force 85hp not circulating water

Thank you for the quick response. I took apart the water pump and the key was still in place. This may sound dumb, but what does a "toasted" impeller look like? Because it still looks ok to me, but then I may not know what to look for.
When I first ran the motor this year I had it in a tub of water. After I saw that I didn't have water discharging I put the muff's on to get some pressure behind the water going into the intake ports. Before I started the testing after I had changed the impeller I left the propeller off, so besides the safety issue is there another reason not to put the motor in gear?
Thank you for your assistance with this.

 

[cwking11]

Re: '87 Force 85hp not circulating water

I have a 1988 Force 85 and I need a lower unit. Can anyone tell me what other year lower units might interchange with this?

 

[Netjunky]

Re: '87 Force 85hp not circulating water

Thank you for the quick response. I took apart the water pump and the key was still in place. This may sound dumb, but what does a "toasted" impeller look like? Because it still looks ok to me, but then I may not know what to look for.
When I first ran the motor this year I had it in a tub of water. After I saw that I didn't have water discharging I put the muff's on to get some pressure behind the water going into the intake ports. Before I started the testing after I had changed the impeller I left the propeller off, so besides the safety issue is there another reason not to put the motor in gear?
Thank you for your assistance with this.

The impeller fins should start to straighten out after you take it out, no groves in the rubber from sand getting in and no cracks in the rubber.

Sounds like you have the water supply. When you had it in the tub of water and the muffs on did you try increasing the RPM in neutral? Any change in water discharge?

 

[john from md]

Re: '87 Force 85hp not circulating water

The two ports below the powerhead are connected to the exhaust by a rubber bellows. If you remove your cowl and look down the back of the motor leg, you will set it. This bellows gets old and hard and breaks. This allows water and exhaust into your leg. This causes the engine to run bad.

Replace the rubber bellows and you will see water coming out of the holes. BTW, these holes are relief holes and really only function to relieve back pressure on the engine when the leg is in the water.

The bellows costs about $10.

Regards,

John

 

[bet123]

Re: '87 Force 85hp not circulating water

Thank you for all of your good idea's. I think I have finally solved the problem.
I took the muffs off and put the lower unit back in the tub of water. Then in neutral I increased the rpm's. It took a couple of minutes of doing this but water started to discharge out of the two small ports. When I shutdown the motor I noticed a lot of crud in the tub of water, so I am assuming that there was some type of blockage somewhere that was cleared with the revving of the motor.