1972 Evinrude 100hp waterpump replacement

dumb tom

Cadet
Joined
Jan 12, 2001
Messages
18
I am trying to get this good ol motor to work. (it does not get above 4000 rpm while on the water). Because the flywheel (and carbs) had been taken off a few (or more) times, I thought I should check the timing, so I put the lower unit in a garbage can and started the motor. No tell tale water. Stopped immediately (ran for maybe 15 seconds), and let sit for 5 min. Restarted motor, same results. Impeller has not been replaced for 15 yrs., so I think it is time to replace. I can get a replacement kit for $140, or just the impeller for $40. (The kit is from a dealer, the impeller is from Sierra).

The first question is-Kit or impeller? Would appreciate any thoughts on this.

The second question is- Any particular hard / trouble spots in removing or reinstalling the lower unit? I know it has the electric shift, so I will have to attach a "retriever" wire, but how will i know if the "conduit" gets damaged, and is there any suggestions for a lubricant to help it slide through. (both in and out)

The third question is- does Sierra make a replacement kit? According to the Seloc manual, an "improved" pump and housing were made, and looking at the OMC part lookup, I see that impeller, housing, and plate part numbers refer to the new part #. If I get a sierra, how will I know if it is the "new" version or the "old" version?

As you can tell, I might be a little confused, but I am trying to do it correctly. Any help/advice would be appreciated! Please let me know if this has been covered in previous posts / topics (and if so, how to find them). I tried searching, but was not successful in finding a relevant response.

Thanks!
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
My advice is take it apart and look to see what's in there before ordering parts. If it has the original pump with aluminum housing, get rid of that lousy thing and replace it with the latest OEM water pump repair kit. That will update it to all the latest stuff.

The shifter cable is kind of risky coming out. Spray some WD-40 or any other lube on it---not that it will do any good other than make you think you are doing something. Oil it up for reinstallation.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
A 1972 engine won't have a tell tale, unless one was jury rigged later.
Dish soap makes a good lube for the shift wire, doesn't rot it like a petroleum product can
 
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