1983 Mercury 4.5 Impeller Question

aquaman8

Recruit
Joined
Jul 27, 2007
Messages
3
Hello All,

I opened up a garage sale 4.5 yesterday to see about changing the impeller. The lower unit came off as per the Seloc manual, as did the water pump cover. When I got to the impeller, I found that 1 vane had broken off and the others were cracked. I also found that the hub of the impeller was badly worn. No key notch left! As well, there was no sign of the key!

Checking for a replacement impeller, I found that there are two part no. listed: 47-89980 and 47089981 (different I.D.). BTW, the motor serial number is 7199681.

Can anyone help me to determine the appropriate Mercury and/or Sierra impeller part number for this motor? The mangled impeller that was in there had 47-89980 molded into thew rubber. As well, a similar number for the right impeller key would be greatly appreciated.

Does this kind of damage sound normal, or should I be looking more closely for damage at the drive shaft where the key sits?

Thank you in advance for any help with this,

Mitch
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: 1983 Mercury 4.5 Impeller Question

There were 2 differant driveshafts dia. thus 2 differant impellers for the shafts, one is for the shaft dia. of .438 and is # 47-89980 or 18-3054 and the other is for shaft dia. of .456 and is part # 47-89981 or 18-3039 you will have to mic . the shaft or slip fit a imp. the latter being hard if your not a service shop. Hope this is some help
 

aquaman8

Recruit
Joined
Jul 27, 2007
Messages
3
Re: 1983 Mercury 4.5 Impeller Question

Hi,

Thanks for the reply. Got the smaller size impeller and it fits fine! Key and notch on the drive shaft llok fine, so I'm happy!

This site is great and thanks again for the help!

Mitch
 
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