1989 Force 85 - Mystery water pump troubles...???

[tipit008]

Hello,

I am thinking about buying a used Bayliner with a 1989 Force 85 hp. Price is very good, but the mysterious water pump circulation problem worries me. I'd appreciate opinons on the possible problem.

The guy hadn't run the boat in a few years. He put it in the water and started the engine. Engine ran fine, but he noticed there was no water at all coming out of the two holes at the back as it normally does.

After about a minute, the thermostat kicked in and shut off the motor. The guy thought the water pump impeller was shot. Bought a new water pump impeller, but when he took the lower unit appart, he found a very healthy (looking) water pump impeller but there was no water circulation...???

To top it off, the part he got is not the right one, so he now has to order another one and wait for it.

Anyway, since the impeller looks fine and is firm enough, is there any other reason anyone can think of why there was no water going into the engine ??

I can get this package for cheap, but I don't want expensive repairs down the road...

Any ideas of what could be wrong would be greatly appreciated.

Thanks.

Marc P.

 

[CV16]

The old impeller should not be hard, it should be flexible.

 

[tipit008]

I'm not a mechanic, but it seemed just right, not too firm, not too soft.

 

[Jiggz]

Since the motor hasn't run in years, there is a good probability the thermostat is stuck closed. Tell him to open and inspect it and test it to make sure it opens or even operational. With a thermometer you can test it on a pot of hot water. Usually, it starts to open around 130 degrees and fully open by 140.

 

[tipit008]

We actually tried to locate the thermostat but weren't sure where it was, in the motor...???

Also, since he ran only about a minute after three years, is it possible something was blocking the water pathway ? Is there a diagram, somewhere, that shows the water pathway in this motor ??

Finally, we compared the firmness of the new (and incorrect) impeller and the old one and they seemed about the same, which is why I doubt the old impeller was to blame.

 

[Jiggz]

The thermostat is located on the upper part of the engine block a little bit off the port side of the back of the engine. It is covered with solid rectangular steel with four 1/4-20 pan head bolts. Here's video showing the location without the cover.

https://www.youtube.com/watch?v=CkaiHR9PNWI

 

[tipit008]

O.k. Thanks. Very helpful for the thermostat.