Impellor Replacement on 76 1150

[shirthero]

Hello,
Working to get this old motor back to snuff, compression good, new plugs and wires, cleaned up cap and rotor, dropped the lower unit-impellor is ugly, only one complete vane left. My question is, how do you get the last of the debris out of the lower unit, there are a few small chunks of rubber down by the water pick up holes. Is there any trick? Where else do I need to look for obstructions? We ran the motor 3 or 4 minutes to check it out in the lake, had good pressure out of the pee hole and the water was hot by the time we were done. Should I have any concern, again, compressions were good, 120-125 on all. Welcome any suggestions

 

[thefairlaneman]

Re: Impellor Replacement on 76 1150

I would blow air through the water pick up pipe . If there are any little fragments of rubber from the old pump or dirt this should do the trick. I also would grease up the new pump to help stop excessive wear when you first crank it.

 

[emckelvy]

Re: Impellor Replacement on 76 1150

If you can't get the chunks out, you may need to remove pump lower base for access to the water inlet cavity. Some lower units have a removable plastic inlet screen but you'd probably have mentioned that!

The base is carefully pried up after removing the upper housing. You'll also need to unscrew the flushing screw from the side, as it'll interfere with removal. You'll need a new base gasket and O-ring. While it's apart you might as well inspect the driveshaft seals & renew as necessary.

Hopefully you've found most of the impeller chunks. Or, whatever made it up the water tube was small enough to get spit out the other end.

Maybe try hooking up a garden hose to the copper water supply tube and flushing thru. Be careful not to exceed 15 psi pressure; if you have tons of water pressure you might blow out some gaskets.

If there's no restrictions or blockages, you should get plenty of water out the telltale and down the middle of the center section (exhaust tower).

Your compression readings don't sound too hurt. You might consider giving it a decarbonizing treatment (use this site's Search feature for Seafoam, Carbon Guard, etc). This'll keep the rings happy.

Take a compression check after a few outings and you'll likely note an improvement. If not, just make periodic checks and you'll be able to spot a deteriorating trend & take action before the motor grenades itself!

HTH & Keep Cool!........ed