1982 Johnson 25 hp water pump installation

[missotis]

Hello, I'm new to the forum and motor maintenance so bear with me. I purchased a Sierra water pump kit 18-3383 with new housing for my J25RLCNB motor. I recognize all the parts except for the o-ring that came with the kit. When I removed the old water pump there was no 0-ring anywhere. Where does this O-ring go? It has a slightly larger diameter than the drive shaft. The only place it seems to fit is just above the drive shaft oil seal below the pump but this does not seem right.

 

[jasper60103]

Re: 1982 Johnson 25 hp water pump installation

Here's a pic. Hopefully it helps.
It could be a part not used on your motor.
Btw, did you get a impeller housing seal (#14) with the kit?

edit: Could it be o-ring (#68)? But you should have two?

 

[missotis]

Re: 1982 Johnson 25 hp water pump installation

Thanks for the quick reply. If you are referring to part 14 in the diagram there is no groove in the cup or the housing for the o-ring to fit there. The cup fits flat and tight against the housing so it does not appear that there needs to be an upper seal and I'm still baffled. My only thought is the water pump is aftermarket so there might have been some changes in the housing from the original OEM waterpump. But why would Sierra have included the o-ing if it is not needed?

 

[jasper60103]

Re: 1982 Johnson 25 hp water pump installation

Yea, its not unusual for kits to have extra parts since they are used on several motors.
But I'm baffled as well that you don't have have a seal (#14) though? I guess the after market kit could be different as you stated. Do you have the old waterpump by chance?

I pulled the diagram for your motor off the BRP section. I'll poke around a bit more. Hopefully the pros will chime in soon.

Btw, I have an 1981 Johnson 25hp, and my manual shows a seal too. I never taken it apart though.

 

[BaitThrower]

Re: 1982 Johnson 25 hp water pump installation

It may be an O-ring for the upper ed of the drive shaft. If there is a recess there just under the upper drive shaft splines, this is probably where it goes. If not, it's likely just an extra part. Some drive shafts had an O-ring up near the upper splines. Some did not. It was the same deal with my Johnson 15hp. Purchased the Sierra kit, came with that O-ring but my drive shaft doesnt have the recess for it, so left in box.

 

[missotis]

Re: 1982 Johnson 25 hp water pump installation

Thanks for the help. Once I dropped my damaged lower unit off the motor I found the plastic spacer above the water pump. The O-ring fits that spacer but there should be two O-rings. Anyway I have a new question on this same water pump. I have now installed the new pump and tightened the bolts down. I can now barely turn the drive shaft by hand. (It is not yet connected to the power head) Is this normal due to a brand new impeller? I was able to turn the drive shaft fairly easily by hand with the old impeller. I just want to make sure before I re-attach the lower unit. Thanks

 

[jasper60103]

Re: 1982 Johnson 25 hp water pump installation

Yea, something is not right. You should be able to turn the drive shaft easily and watch the the prop turn if its in gear.
I would try to isolate the problem. Unbolt the waterpump housing and slide it off then see if it twist easily then.

edit: I searched some of the old threads. I guess some extra friction is normal. When I changed my impeller I didn't notice any additional friction though.

 

[missotis]

Re: 1982 Johnson 25 hp water pump installation

I read on an old thread to try a little dishwashing liquid to lubricate the new impeller. Two drops of Joy and I am now in business. The new impeller was just too stiff to turn freely against the cup. Thank you iboats!