Alpha 1 impeller

[Fishbuck]

Most of the threads say to replace the whole kit and not just the impeller. Why?
Mine just had a kit put in last year and I don't think it got much use after.
Why can't I just replace the impeller. Looks much easier and quick than replacing the housing etc.
Also, the boat overheated and I shut it down and got towed home.
Next day I ran it with the hose and it ran at a perfect 143 degrees for about 1/2 hour. I did fiddle with the thermostat before I ran it again.
Why did it overheat?

 

[Sundancer]

Why it overheated is always a mystery. Did you try restarting it after you got back to the launch? You may have picked up a bag or something that prevented water from getting into your drive. If it ran fine on the hose, I'd guess your impellar is doing it's job.

I usually inspect the impellar and housing. Most of the time I just replace the impellar, but the housing wears and needs to be replaced periodically too. Some folks figure it's cheap insurance to replace the whole housing every year. I've never seen the need to do that based on the way I use the boat, but I spend most of the time in freshwater. Where you boat and how you boat will determine how long either will last. Sand and salt arne't good!

 

[Daddubo]

I had the same problem ran great at home got hot in the lake. I pulled the t-stat it had a 160 in it I put a 142 in it and it is fine now runs between 160 and 170 under load. Remember that the house water is colder 55 to 60 deg the lake water is in the 80's plus you are forcing the water in at home and sucking in the lake.

 

[SCORPIO]

Its not that much harder or much more expensive to do the whole thing as opposed to just the impeller. Those are flimsy looking plastic waterpumps to begin with(compared to the old OMC which were cast aluminum). If you overheated, the housing could be warped enough to cause clearance problems for your new impeller and it may not pump as well as it should or for as long. It will take you just as long to drop the lower unit and reassemble to do the impeller as it will to do the whole thing. For me, I do the entire kit and be done with it for a year or two.
JMHO

 

[Fishbuck]

Hi Everyone!

Okay I replaced the thermostat and gave it a little test run. Seemed okay but did overheat again. So much for the easy fix.
Took the lower unit off and got the impeller out. No damage to it. But the housing is another story. At the top of the housing there is a rubber seal. That was damaged and my best guess is that it was pumping enough water out there that at idle and low RPM's it was pumping the water out the top of the housing. The housing didn't seem to fit the shaft exactly centered either.
So I put the new impeller in and the new upper housing. The new one didn't fit exactly centered either. Hope it lasts a while.
But I can see this as a weak spot for sure. Maybe I'll try to adjust the housing mounting holes next time. Definately something to change before it goes bad.
Splashed it in the bay and made a few runs with it and no overheating.
Next project is the alternator. It isn't charging enough to keep the battery up.
My friend who helped me with the impeller isn't an electrician and neither am I so his friend who is can trouble shoot it for us. Alternators aren't cheap either so I hope we can fix it without replacing it.
Almost there. Few more things to do.
Can wait to tear up the water with this little hotrod!

 

[Daddubo]

Put a volt meter on it to check the voltage coming out it should be around 14V if you don't have one go to Radio Shack they have a nice small one for around $20.

 

[eman369]

sorry daddbo I did not see your post absolutely correct