1960 johnson40hp lower unit

[fishbait43]

I just bought this boat that sat for about 17years covered up in a heated garage.To my surprise the motor runs very strong but it appears that water is getting in the lower unit.Can anyone please tell me how difficult it is to replace the seals? also is there any special tools needed?

 

[tashasdaddy]

Re: 1960 johnson40hp lower unit

1st are the sealing washers on the fill and vent screws, is it a little or a lot of water. the fill and vent screws are the #1 place for leaks without the washers.

 

[fishbait43]

Re: 1960 johnson40hp lower unit

It aapears to be a fair amount.I replaced the impeller but didnt know of any gaskets.I have been using the hose attachment when running motor only for short time.My thought is that the seal around the shaft below the impeller is shot.

 

[larky]

Re: 1960 johnson40hp lower unit

not to hard to replace the lower unit seals just take your time. a couple of hard spots are the shift rod bushing( do a search and you should find all the info needed) and the seal just below the impeller. the best way i found was again to be patient and to buy a seal puller from sears($11.00). try not to damage the area that holds the seal. the rest should be staight forward

good luck

 

[spy1309]

Re: 1960 johnson40hp lower unit

I have the same motor like yours and I run it in a test tank ( garbadge can ) the leak I got was from the washers as somebody already mentioned.
Just curious how do you install the hose attachement to my knowledge on this motor you can t run ear muffs or hoses.

PS - can you tell me what your motor compression is? Mine is ~100psi and I think is kind of low and I want to compare it with some identical motor.

 

[R.Johnson]

Re: 1960 johnson40hp lower unit

As I stated in an earlier post, you can make a sheet metal copy of the inlet plate that fit's above the cavitation plate, and solder on a female hose connection. This works well for any of the older engines where you can't use muff's.