1965 Seahorse 18hp - water stopped ejecting?

[stjon]

I have finally got my engine running with a reliable tickover! Had a misfire but put a new HT lead on and that seemed to sort it! However, I left it running for a good 5 minutes in a barrel with no problem and loads of water ejecting from the exhaust, when the water suddenly stopped flowing. Tried giving it a quick rev up but nothing. I had to stop it pretty quickly in case I was damaging anything. I was just hoping there might be a reason for the flow to stop (thermostat opening?) that didn't involve a new impeller....

 

[Bob_VT]

Re: 1965 Seahorse 18hp - water stopped ejecting?

Check the impellar ........ they do fail. That would be my absolute first step.

 

[kbait]

Re: 1965 Seahorse 18hp - water stopped ejecting?

If you had the barrel water above the waterpump 'bulge' - and impeller submerged - it should keep pumping some water out the exhaust even if the thermostat stuck closed. My guess is you had one or 2 impeller veins w/cracks and they just let loose.. no more water pumping. To be sure, you can remove thermostat and test again, but my guess is you'll get no water discharge. Again, if your water-depth in the barrel was good upon initial test.

Good luck!

 

[kfa4303]

Re: 1965 Seahorse 18hp - water stopped ejecting?

+1. Gotta use a test tank on these old motors and if the impeller/waterpump is old it will need to be replace. It's a cheap, DIY job. You can get an impeller here at iboats for about $20. Here's a great link that can walk you through a tun up from top to bottom.

Maintaining Johnson E & FD Serie