1989 85hp Force on Muffs?

[LarsMN89]

I am replacing the water pump impeller on my 1989 85hp Force. Since the lower unit was off I wanted to see how much water got to the impeller with just the muffs on. I have rectangular-shaped muffs with water supply to each side. With water faucet on full (approx 80 psi) I get no water to the water pump. Is this normal? Does the impeller have to be turning to get water up that high? The water lines are open in the lower unit are open - water drains out the bottom when I pour it in from the top.

 

[BlueFishCrisis]

Re: 1989 85hp Force on Muffs?

I successfully circulate water through my 89 125hp Force L drive with an 85hp lower unit on it. Water on full, but it does circulate properly......

 

[Jiggz]

Re: 1989 85hp Force on Muffs?

Actually, if you lower or close down on the faucet a little bit you might get water into the impeller. The reason is water takes the path of least resistance. And when you open the faucet all the way open, the back pressure lifts the muffs off the surface thus providing a path of least resistance for water to flow out of the muffs instead of to the impeller. And yes with the impeller not rotating there will be less water going to the water tube.

 

[pikefisherman]

Re: 1989 85hp Force on Muffs?

Good to know I wondered why my muffs would not work, hopefully I can get rid of the wash tub.

 

[jerryjerry05]

Re: 1989 85hp Force on Muffs?

If you have a wash tub deep enough to cover the cavitation plate by 2-3in then keep the tub.
The impeller can actually stop the flow unless it's turning.

 

[Big Fish Billy]

Re: 1989 85hp Force on Muffs?

I preferred the tub on my Force 40, my muffs just didn't fit tightly enough...

 

[hrncjar]

Re: 1989 85hp Force on Muffs?

what i did was got a 1000ltr water/chem tank with the cage around it im sure you have them where your from, i just cut the top off to suit the hight of my motor on my boat to fit so i can reverse my boat up and get it into the tank, then fill the tank up to the hight of the motor which on a chrysler is just above the exhaust area, and when you install new water pump/impella it takes a while to get up their so i just rev it a little in cold start, untill it pumps water out of the tell tail, and then just put in nuteral to warm up and let it run for a little while around 10mins. iv found the ear muffs can be a pain in the backside, only use them when im away from home and want to flush my motor. hope this helps good luck

regards shaun

 

[oldboat1]

Re: 1989 85hp Force on Muffs?

Muffs are OK for flushing IMO, with reduced water pressure from the hose, but running in a barrel is preferred to let the water pump fully operate (can't really tell if a water pump is failing if using a flusher), and to provide back pressure for testing engine operation. The leg should be deep, a few inches above the impeller location. Run at no more than a fast idle, and a good idea to keep water from the hose flowing into the barrel to keep the level up, to cut down on the amount of exhaust debris getting sucked up back through the water passages, and to keep the water in the barrel from getting too hot.