1989 85HP Force Water Pump

[fosser2]

I recently bought a Bayliner Bass boat for cheap and decided to make it into a side project. Everything has been going well until I got it running. While the boat is running the engine gets very hot and I am forced to turn it off for fear of overheating. I spent the other night dropping the lower unit (thanks Frank for the tutorial) and changing the impeller and gasket. The impeller that I took out was in fairly decent shape yet but I changed it anyways. Upon putting everything back together I put the motor in a bucket and tested it out. The motor was still getting hot very quickly. I put my hand down where the water intake vents are on each side of the lower unit and noticed there was no suction at all. I then took the thermostat completely out and the "tell-tale" plug and tried again to no avail. I am hoping someone can direct me what steps need to be taken to resolve this issue. Thank you in advance for the help.

EDIT: I have attached a picture of the impeller housing. I think its still in ok shape.

 

[Oregonbayliner]

Thermostat?

 

[glenn property of pam]

have to ask .........how are you getting that lower unit in a bucket? the water inlet has to be under water and stay under water even with all the exhaust gases blowing around so the water needs to be at least as deep if not 1" deeper than the cavitation plate (flat piece over the prop). Take a hose pipe while the lower unit it off and shove the end up the water inlet pipe where the water pump connects then see if water will exit the tell-tale hole.

 

[jerryjerry05]

Like Glen said: has to be deep in the bucket.
At least 2-4 inches OVER the plate.
When you put the boat in the water the cavitation plate is usually under water.
These pumps are not self priming. No suction.
You can use muffs on a STRONG hose.

 

[fosser2]

Thermostat?

As I said above, I ran it without the thermostat attached to no avail.

have to ask .........how are you getting that lower unit in a bucket? the water inlet has to be under water and stay under water even with all the exhaust gases blowing around so the water needs to be at least as deep if not 1" deeper than the cavitation plate (flat piece over the prop). Take a hose pipe while the lower unit it off and shove the end up the water inlet pipe where the water pump connects then see if water will exit the tell-tale hole.

I should have specified that it was a large bucket (or so I thought). I had the prop and quite a bit of the lower unit under water. I can say the cavitation plate was not under water though. My setup was the same as this video... On a final note, I used an air compressor to blow from the lower copper water pipe up through the motor and through the tell-tale hole & thermostat hole. Air seemed like it was blowing through just fine. I also blew from the top down and it flowed well both ways. I did not try purging with a hose, so I suppose I will give that a shot tonight.

EDIT: Do you think the motor in this video was primed before running?

 

[foodfisher]

I'd venture to say, the motor in the video will overheat too. Edit: There is no actual priming. Water reaches the pump or it doesn't.

 

[fosser2]

Well I got home today and decided to try the boat on muffs. Seems like the water pump is doing what it should. The block still gets pretty warm but it is an engine so I believe it is OK. I have posted 2 videos of it running and I would like to hear what other have to say about it. Thanks.

 

[fosser2]

Other video because I can't post 2 at once. Both videos were shot with the engine on idle.

 

[foodfisher]

Wow, when it was suggested to try running without a thermostat, I'm pretty sure the cap should be replaced. Since you did it a without anyway, there's practically no water flow there. I'd dunk the lower deep in a bucket or tape the ears tight or search for a restriction somewhere. You did inset the key with the new impeller?