1958 johnson seahorse 10 hp

[tkwalla]

I bought this old boat and motor the other day. We pulled it out of the barn and after sitting for a couple of years it fired right up even on the old gas that was in the tank! The only problem.. not pumping water. I got the part and started to replace the water pump but cant seem to get the foot to drop. I was hoping there was someone here that could help. The model number is QD-18

 

[Stickler]

Re: 1958 johnson seahorse 10 hp

I believe if it has fwd N Rev, you have to remove the powerhead and disconnect the shift linkage before dropping the lower unit.

 

[HighTrim]

Re: 1958 johnson seahorse 10 hp

No need to remove the power head. There is a shift rod coupler halfway up the leg. Remove the access panel, then remove the lower bolt from the coupler, and the gearcase will slide down.

Post a pic, I love the '58 linuep. I have a couple nice '58 QDs myself.

 

[colbyt]

Re: 1958 johnson seahorse 10 hp

The attached pdf might help you. Best viewed at about 70% of max.

View attachment JOHNSON EVINRUDE 276-277.pdf

 

[kfa4303]

Re: 1958 johnson seahorse 10 hp

Here are a couple handy links.

Johnson

1958 Johnson QD-19 10 hp Outboard Motor Parts

 

[64osby]

Re: 1958 johnson seahorse 10 hp

Real nice motors and easy to work on.

The fine gentlemen here have guided me through a reviving a few motors of the same vintage.

:welcome: to the best boating site on the web.

 

[tkwalla]

Re: 1958 johnson seahorse 10 hp

The attached pdf might help you. Best viewed at about 70% of max.

View attachment 190116

I tried taking the bolts out in the access panel but I couldnt get the shaft to come apart. Do I just need to force it lose? Thanks for all of yalls help.

 

[tkwalla]

Re: 1958 johnson seahorse 10 hp

I cant post any pics because all I have is my smart phone

 

[HighTrim]

Re: 1958 johnson seahorse 10 hp

If you removed the lower bolt out of the coupler, you should be able to pull the gearcase out.

 

[tkwalla]

Re: 1958 johnson seahorse 10 hp

Ok so I got the gearcase off and opened the water pump housing but the impeller looks fine. Is there another reason why it wouldnt pump water and should I still replace it?

 

[HighTrim]

Re: 1958 johnson seahorse 10 hp

That is a judgement call. I hate to open things up and not replace the impeller myself though. Especially when you are having trouble, and do not know the age of the impeller.

Is the housing worn/grooved at all? Impeller plate worn/grooved? Vent open on top of housing? Condition of grommets on water line, both ends? Intake clear and open?

Shoot compressed air or water up the copper water line and ensure it exits the exhaust relief port to rule out blockage of the cooling circuit.

 

[colbyt]

Re: 1958 johnson seahorse 10 hp

Ok so I got the gearcase off and opened the water pump housing but the impeller looks fine. Is there another reason why it wouldnt pump water and should I still replace it?

Looking fine and being fine can be 2 very different things. Is the impeller pin securely attached to the shaft? Is the impeller cupped in one direction (comma shaped)?

 

[BassBlaster29]

Re: 1958 johnson seahorse 10 hp

Did the motor get hot? Just wondering what brought you to the conclusion that its not pumping water? These old motors dont have a "pee hole" like modern motors.

If your model number is correct your motor is a 57.

 

[tkwalla]

Re: 1958 johnson seahorse 10 hp

Thanks for the correct year. I didnt see any water coming out anywhere so I didnt want to take the chance of running it hot. Also there was a broken o-ring that I dont know where it came from. This is my first water cooled outboard so thanks for all the help.

 

[HighTrim]

Re: 1958 johnson seahorse 10 hp

There should be a steady gush of water out of the exhaust relief. Very noticeable.

 

[colbyt]

Re: 1958 johnson seahorse 10 hp

There should be a steady gush of water out of the exhaust relief. Very noticeable.

Absolutely correct. It should be a flow equal to a horse. You can't not see it if it is there.

 

[kfa4303]

Re: 1958 johnson seahorse 10 hp

Hello again tk. Here's a vid of what you want to see when your motor is running properly in a test tank. If it ever fails to pump water, shut it down so you don't risk an overheat.

1957 Johnson 10hp Outboard Motor - YouTube
1958 Johnson Seahorse 10 hp - YouTube

 

[tkwalla]

Re: 1958 johnson seahorse 10 hp

So I got everything done. The only problem now is that when I put the last screw in the housing to tighten it down... the screw hole in the foot is stripped!