Roasted my impeller (pictures attached) what parts should I buy?

1987 wellcraft elite with 260/350 mercruiser I/O

I had a squeeky altenator belt which I replaced. I decided to put a new belt on and test it out. So I put the muffs on and was running it when my wife came out to tell me she needed me to move my truck so that she could go to the food store. I jumped out of my boat, backed up my truck and jumped back in my boat when i noticed steam comming out of my drive. I looked at the temp gauge and it was 230 and rising so I shut it down. Turns out my dumb *** parked my truck on the garden hose and it was pinching off water flow to the muffs. I moved the truck off the house and started th eengine and the temp slowly cambe back down to normal. Water was still coming out of gimble housing but not as much as before. I was pretty convinced I wiped out the impeller. I have a spare impeller new in the packaging. When I bought the boat 2 years ago I had the drive serviced and they put a entire sewater pump kit (parts cost $45 according to my reciept) Last night I read how to pull the lower unit off and I did. It seems I caught it in time by th eattached pictures. I was going to buy the kit for $45 today but seeing as how I already have the impeller I think I will just replace that. Seems that the top of the impeller roasted but not the bottom, I suspect there was water in the bottom. Judging by the look of the upper housing, I think I may just but the upper housing to play it safe. I think I will just buy this one piece. You guys are the experts. What do you think?

Re: Roasted my impeller (pictures attached) what parts should I buy?

Myself, it were just routine maintenance I would just change the impeller. Since it melted the way it has, I would to the compete kit and the base with OEM parts.....

which would include:

Quicksilver 46-96148A 8 (Water Pump Upper Housing Repair Kit)
Quicksilver 46-44292A 3 (Lower Base Kit for an Alpha One)

Re: Roasted my impeller (pictures attached) what parts should I buy?

+1 Eric, you need the entire kit, not just the impeller. Reason: the water pumped by the impeller serves two purposes, to cool the engine and manifold(s) and just as important cool the exhaust . The hot exhaust (during the time of no water flow) could have caused other damage, so a complete impeller kit would be wise, better safe than sorry IMHO.

Re: Roasted my impeller (pictures attached) what parts should I buy?

Ok, I will get the upper kit. I will just hold onto the impellor I have.

Re: Roasted my impeller (pictures attached) what parts should I buy?

Might want to check the exhaust block off plate (plastic) that is held on with four bolts, at the top of the cavity in the upper unit. This is where the vertical drive shaft slips into when you re-assemble lower unit to upper unit. This plate is plastic and can warp/melt in a no-flow situation due to super-heated exhaust gasses. It's worth checking to make sure it's not damaged, too.

Re: Roasted my impeller (pictures attached) what parts should I buy?

Augie56 said:

Might want to check the exhaust block off plate (plastic) that is held on with four bolts, at the top of the cavity in the upper unit. This is where the vertical drive shaft slips into when you re-assemble lower unit to upper unit. This plate is plastic and can warp/melt in a no-flow situation due to super-heated exhaust gasses. It's worth checking to make sure it's not damaged, too.

Click to expand...

Not sure if Augie is talking about the Water Pocket Cover, but be sure to check that and the seal. If it is roasted, post pictures and check back in before taking it apart. It can be a real PITA. Would have to have the experts (...certainly not me) walk you thru that one.

Re: Roasted my impeller (pictures attached) what parts should I buy?

Yeah, he is talking about the water pocket cover with the copper tube. I checked it and it looked normal. If it was deformed I would be concerned about exhaust getting back up into the water inlet. But it looks ok to me. Good thng too, those bolts look comfortable where they are.

I took Eric's advise and looked at the lower housing and I see slight evidance of melting around the shaft orifice so I will prpobably buy the kit today. Since this perpetual rain storm we are having in the northeast this week I have time to do it right. Or at least whet i think is right...ha!

Re: Roasted my impeller (pictures attached) what parts should I buy?

Thanks for the correction, yes I was referring to the Water Pocket Cover....if that thing gets roasted, too, then you'd be sucking exhaust gas back into the cooling water circuit and will likely cause a temperature runaway/overheat situation. Make sure it's good to go before re-assembling the outdrive.