What does a bad water pump look like?

aamyot

Cadet
Joined
Nov 14, 2009
Messages
24
Hi Forum,
A buddy and I are trying to revive a '78 Johnson 115HP. We started by reading BoatBuoy's fantastic sticky on awakening a sleeping outboard. It's been really helpful. We've taken it slow, solving electrical problems and some stubborn cylinders and now we are on to the water pump. This engine has been in storage since 82 and probably only saw a handful of hours since it was bought new in 78. I took off the lower unit (which had a good amount of sand imported from the Keys) and opened up the water pump. To my surprise, the impeller looks good as new. It's still pliable with no cracking or dried up bits There are no signs of wear or rubbing inside the pump.
Question is: What am I looking for? Is this impeller good to go or should I just replace it on principle? I already bought a new impeller based on the assumption that the 30 year old one would be trash. It was about $50. I would love to apply this to some other needed parts if I can. Thanks for any expert input.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: What does a bad water pump look like?

change it any way. 30 year old rubber will come flying apart at 4500 rpms, remember that is attact to the drive shaft and turns the same rpms as the motor. while you have the lower off flush the water tube.

they should be change every 2-3 three years,
 

royal0014

Master Chief Petty Officer
Joined
May 6, 2010
Messages
874
Re: What does a bad water pump look like?

Not an expert, but answer this question: How hard was it to drop the lower unit? Would it be worth the $50 to drop it again after only one time on the water? Just my thoughts.........
 

wellsc1

Petty Officer 1st Class
Joined
Apr 7, 2009
Messages
328
Re: What does a bad water pump look like?

Change the impeller. I learned the hard way, not changing my on a motor bought used that sat up for a few years. It cost me $800 due to an engine overhaul caused by impeller that came apart, burning up the engine.
 

aamyot

Cadet
Joined
Nov 14, 2009
Messages
24
Re: What does a bad water pump look like?

Thanks, Everyone.
I went ahead and did the impeller replacement. Glad to have the good advice.
 
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