Old johnson V4

[metalchewy]

Was helping clean out my dad's shop last weekend and in the corner was an old V4, 75HP, 62 johnson model V4A 14L.

It sat for 10 years in his shop, an older guy in town had given it to him before he passed he probably had it as long as well.

Not sure what I'll do with it. It's too heavy for our boat. Thinking of making it run (if it will) and selling it. Not really sure if it's something anyone would want.

Dry Compression.
Right 87 and 80
Left 85 and 80.

Wet compression is 91 on all 4.

If I do take this on, first place to start is the fuel pump. Diaphragm, bowl(missing), filter, bowl attaching hardware and see if I can make it run and it doesn't knock.

Thoughts?

 

[airshot]

Uncle had one when I was a kid (76 now) and boy was it a gas hog. My guess would be no one wants a motor that old and a fuel hog unless they are looking for something historical to match a boat or something. Might be a fun project if you into that type if thing. Value in my opinion is next to nothing...small old motors are far more valuable.

 

[racerone]

Your location?=====Do you have the electrical junction box that mounts inside the boat?-------Do a lot of testing / inspection BEFORE you spend a $ on it.

 

[metalchewy]

Your location?=====Do you have the electrical junction box that mounts inside the boat?-------Do a lot of testing / inspection BEFORE you spend a $ on it.

Location is Las Vegas area.

It came from northern Utah. The old boat it came out of sat for years in a field behind the barn of the original owner (also passed away). I didn't see it the boat there when I was up there. So I don't have wiring, junction box, controls or linkage.

 

[racerone]

Test electric shift and a few other things before spending hard earned beer tokens.

 

[metalchewy]

Test electric shift and a few other things before spending hard earned beer tokens.

Will do, thanks for the advice.

 

[Chris1956]

The early V4 engines had those downdraft carbs. I had two 50HP V4s (Fat-Fiftys) from '58 and '59 and I never thought the carbs were real good. They allowed un-atomized, liquid fuel to enter the intake manifold and crankcase.

In order for the motors to idle smoothly, any liquid fuel that built up in the intake manifold or crankcase was blown out into the water.

So, the carbs didn't atomize all the fuel, and the motor used crankcase pulses to keep the crankcase and manifold free of liquid fuel. The crankcase pulses were composed of fuel -air combustion mixture. It is therefore no wonder that the motor used/wasted a lot of fuel.

OMC did an endurance test of the '58 50HPV4. They put 2 of them on a 23 footer and ran it across the ocean to Europe. The support ship pulled a fuel barge and the two Fat-Fiftys burned 1500 gal of fuel, during the voyage. They clearly proved that the motor was very reliable.

 

[metalchewy]

That's a whole lotta fuel. I was told this thing didn't get good mileage when it was pulled.

 

[racerone]

You will need that junction box and a control box for electric shift.-----Smooth running motors,----They are thirsty.----Depends on how many hrs you put on in a season/----Not much point in spending $10,000 for a new motor to save $200 / per season on fuel.

 

[Chris1956]

On my Fat-Fifty, I modified the purging system so that the liquid fuel would be captured by a fuel tank in the boat, and the crankcase vapors would be burned. I estimated that about 1/6 of the fuel would be purged from the intake manifold and crankcase.

 

[jimmbo]

If you decide to work on this Engine, beware that a special Tool is required to position the High Speed Nozzle properly in the carb body.
Also you would need to use BRP Precision Blend in the Gear Case. That is what BRP calls its Type C gear oil. While there are some 3rd party gear oils that claim to be Type C, they also have a Disclaimer on their Labels that they are not useable in Electric Gearcases

 

[metalchewy]

Thanks, I did not know that about the special tool, or the BMC gear oil. If we decide to get that far into it, this is very useful.

Need to order a manual, to act like I know what I am doing when checking it out.

 

[Crosbyman]

you may want to invest 20$ in this easy to download book to service your fuel burner

1958-64 Johnson 50,60,75HP 306775 Outboard Service Manual

1958-1964 Johnson 50,60,75 HP Outboard Motor Service and Repair Manual # 306775 50hp - V4, V4S, V4L, V 4S, V4SL, 60hp - VX, VXL, 75hp - V4S, V4SL, V4A, V4AL, V4A., V4AL .pdf download

watercraftmanuals.com

 

[metalchewy]

you may want to invest 20$ in this easy to download book to service your fuel burner

1958-64 Johnson 50,60,75HP 306775 Outboard Service Manual

1958-1964 Johnson 50,60,75 HP Outboard Motor Service and Repair Manual # 306775 50hp - V4, V4S, V4L, V 4S, V4SL, 60hp - VX, VXL, 75hp - V4S, V4SL, V4A, V4AL, V4A., V4AL .pdf download

watercraftmanuals.com

Thank you. That gave me the part number I needed to find a printed version. I do better turning pages than having it on a screen.

 

[airshot]

If you choose to get this motor up and running, keep in mind this will be a labor ( and expense) of love, you won't get your money back and it isn't an investment. Something some folks just enjoy doing....