1989 Johnson 88 Impeller Key??

BigNuge

Seaman
Joined
Nov 29, 2018
Messages
65
Hey guys, got a couple questions that have popped up while trying to do my water pump today.

Got the lower unit out, on the bench. Pulled the pump housing, old impeller, old key (very worn), wear plate, and cleaned the gasket surface.

I go to start putting things back together and I notice that instead of a “half moon” metal key they gave me a wedge shaped plastic “key”. After some searching it sounds like some OB’s use these plastic wedges, and that the wedge rests in a flat spot in the shaft. Well, mine doesn’t have a flat spot, it has an actual key groove that accepts a small metal half moon key (like the one that came out of it). All other parts of the water pump kit match, and fit. It’s just this key issue that has me stopped. Now, if my old key wasn’t so worn I’d just reuse it, but that’s not possible. Any input on this?? I went back and checked the application chart for the kit I got, it lists the Johnson 88.

In the end I have to get a new key for this impeller. My second question, does anyone know of a part number/size for the metal half moon key that I need? I will likely just use the old impeller, it’s still good and healthy looking, and the rubber is still fresh (fins are nearly straight again after sitting on the bench for 20 minutes).

Thanks in advance!
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,395
You do not have the original lower unit on your motor !----Or the driveshaft was replaced with an older part.---Look it up for an older V-4 till you find the # for the stainless " half moon " key.
 
Last edited:

BigNuge

Seaman
Joined
Nov 29, 2018
Messages
65
Just found it thanks to your input! Thank you!

So the lower unit is a 70’s vintage?? I can’t believe it would bolt right up to a 1989?! The engine has a date of 3-89 right on it.

To your knowledge, are there any other notable differences I should be aware of?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,395
And why do you think older parts would not fit ?----Pistons on these V-4 motors are the same from 74 to 98 models !!
 

BigNuge

Seaman
Joined
Nov 29, 2018
Messages
65
Lol, no offense intended....I just didn’t know that so little changed between motor variations.

I’m glad to find this out! At least usable parts are plentiful with so many parts being interchangeable.

The motor runs really nicely, I’m looking forward to using it for years to come!
 
Top