Westerbeke generator loses water flow.

[Almightys]

I tried to start my generator yesterday but noticed no water pulling through and shut her down. Today I took the cover plate off and impeller was toast. Mossi g three vanes. Bought a new one and installed. That part went fine. I pulled the end caps off heat exchanger and found some pieces of impeller. Removed those. When I started it up, it took a monte to get water through system. Told the wife to watch it and after about a minute or two the water stopped flowing. hmmmm
Went back to the heat exchanger and pulled both sides off again, nothing. For giggle I told the wife to start it again. Ran fine for a few min with water punching g through then stopped again. Any ideas?

 

[Thisisit]

Any issues with the low pressure side? Perhaps a blockage between the seacock and pump?

 

[FootballFan]

Any issues with the low pressure side? Perhaps a blockage between the seacock and pump?

Could it be a blockage outside the boat where the through hull is?

 

[bahamabreisus]

Crazy, but years ago we had a friend with 500 also. They sucked a stick up the thru hull, took for ever to figure that one out.

 

[Almightys]

Any issues with the low pressure side? Perhaps a blockage between the seacock and pump?

So I did take the lower hose from pump to heat exchanger off and started genie to see if water was coming through. All good there. Hooked it all back up again and started genie again. Same deal, water flow for a few min then nothing.
The exhaust water flow port on the hull is separate from engine exhaust. It’s above and out of water so nothing blocking

 

[Almightys]

I

Crazy, but years ago we had a friend with 500 also. They sucked a stick up the thru hull, took for ever to figure that one out.

I hope it’s not that, water still very cold here. I did loosen the strainer and water was flowing right out. Capped it back off.
This is the first time trying to start genie for the season since launch a few weeks back.

 

[dtfeld]

How old are you genie hoses? Maybe collapsing on the inside?

 

[Thisisit]

I

I hope it’s not that, water still very cold here. I did loosen the strainer and water was flowing right out. Capped it back off.
This is the first time trying to start genie for the season since launch a few weeks back.

Since the strainer isn’t the issue. Work towards the seawater pump. Check the hose between the strainer and the impeller housing for blockage.

 

[Almightys]

Ok check strainer again and a few other things. Looked like one of the hose clamps on the inlet side of pump was loose (leaking water) tightened and this time got out and started the thing myself while watching flow outside boat. It did the same thing and started to slow then nothing. I said f it and let it keep going. Within about another half a minute the water came back and stronger. Let it run 5 min and still stayed strong. Must have been a bubble in the system or something. Thank god it’s fixed. Leaving the dock with no fridge or ice maker is just not why I bought this boat
Thanks for the suggestions you guys rock and forced me to go back and look over the whole system.

 

[370Dancer]

or, an air leak in the hose, or a loose hose clamp. Any air getting into the suction side will eventually starve the impeller of water, and then you have an air lock..

 

[Thisisit]

Yup and then water slowly takes up the air space once you shut it down. On start up, water flows again until the same thing happens. Luckily, most problems are simple fixes. This time F it worked! One of the better tools in the box. Glad it's all fixed.