Alpha One not sucking in water for cooling?

[garyoNC]

I have a 1988 Alpha One 5.0L Mercruiser. The stern drive has water inlets on both sides. After getting it ready from winter storage when running the engine I noticed no water was coming out of the prop with the exhaust. I have a dual water flusher hooked up to the hose and water just squirts out from the sides. Everything I could think of led me to the lower unit water pump. I pulled it apart today and everything looks okay. The impeller blades are a little curved so I guess I should replace it. But nothing I saw indicated that no water could be sucked in and circulated. Anybody have any ideas?

Thanks,
Gary

 

[Bondo]

Re: Alpha One not sucking in water for cooling?

The impeller blades are a little curved so I guess I should replace it.

Ayuh,.... And if the end plates are scored,.. Replace the housing too...

 

[garyoNC]

Re: Alpha One not sucking in water for cooling?

I saw a previous posting about overheating problems and it might have even been you that said to pull off the inlet side of the thermostat housing which comes from the stern drive and flush it out. It had very good water flow both ways, no restriction at all so I'm hoping it will be the impeller. No one has one locally so I guess I'll order it online.

Thanks,
Gary

 

[Evinrude Boater]

Re: Alpha One not sucking in water for cooling?

When you have a hose connected with muffs, the lower unit pump doesn't have to pump since you have the water under pressure. Did you warm up the engine until the thermostat opened?

 

[CharlieB]

Re: Alpha One not sucking in water for cooling?

After getting it ready from winter storage

How long did you let it run?

Remember that it first has to fill the block and exhaust manifolds before any water exits the boat.

Did the engine begin to heat or was the exhaust manifolds hot?

 

[garyoNC]

Re: Alpha One not sucking in water for cooling?

I ran the engine for about 15 minutes and the temp just went over 200 degrees. Last year it would sit at around 160 degrees all the time. Yes the engine started to get hot.

 

[ENSIGN]

Re: Alpha One not sucking in water for cooling?

Be Smart,replace The Impeller And Housing,ted Baltimore,md.

 

[CharlieB]

Re: Alpha One not sucking in water for cooling?

After you finish servicing that water pump, disconnect the water line from the transom where it attaches to the T-stat housing, fire the motor for just a minute and observe water flow to ensure no restriction in the line or p.s cooler.

Pull both T-stat outlet hoses to the exhaust manifolds to check the flow control balls (if your model is so equiped) to ensure they are not stopping water from exiting the motor.

Lastly, exh risers outlets can rust and restrict water flow, but I haven't yet seen BOTH side totally clogged and NO outlet flow.

 

[garyoNC]

Re: Alpha One not sucking in water for cooling?

Thanks all. I ordered the impeller and will get it in as soon as I get it. I will then run with the hoses disconnected and check flow.

Gary

 

[cosmic coho]

Re: Alpha One not sucking in water for cooling?

don't forget to check fresh water pick-up hose from outdrive to transom...my just had same problem, and hose had pulled off when outdrive was in up position an turned all the way to the right....hose was pinched inbetween u-joint bellows and transom plate, so it was holding it back on full extension.