1970 Johnson 60 hp coil test

Joined
Jul 19, 2010
Messages
12
Ok I have a 1970 60hp Johnson that has been nothing but a headache for me from the beginning and I cant even find parts for the thing anymore. So if you got some let me know. Anyhow it will start and run. It idles just fine but once I get about half throttle or a little more it just nose dives. I touched the coil and it was hot on the bottom side. How do I test it to make sure thats the problem. Im going to do the automotive coil conversion but for better research I want to know everything that I fixed not just hey that worked and im not positive why.
Thanks so much. let me know if you need any pics. I have a iphone and ill be working on the boat all day so im only a few seconds away. I can text pics to or whatever.
 
Joined
Jul 19, 2010
Messages
12
Re: 1970 Johnson 60 hp coil test

Test for voltage at the amplifier input with key on. If ok, go to next step.

Remove the coil and then unscrew the spark lead from the distributor cap by turning the whole coil and wire assembly. Then re-mount the coil and rig up a 1/4" spark gap off the end of the wire.

Now, disconnect the wire running between the amp and timer base under the flywheel. Turn key on. Brush the amplifier end of the timer wire across a bare metal grounded part. There should be sparks off the end of the spark wire.

If you get sparks, the amplifier and coil are good. Pull the flywheel and see what is wrong in there. But if no sparks, you have a bad amplifier or bad coil. Take your pick.
Ok I done this test and everything checks out good. But my amplifier is getting hot on the bottom side. Points are new. Um wires have been checked and many replaced. Plugs new. Gap and timing good. Carbs all cleaned and set. :confused:
 

Mntom

Petty Officer 2nd Class
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Jul 14, 2010
Messages
140
Re: 1970 Johnson 60 hp coil test

Dumb question, but when it starts to fall on its face have you bumped the choke to see if that will make any difference? If it helps then you are running lean on the high speed jets.
 

rayodunne

Petty Officer 1st Class
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Jul 21, 2006
Messages
224
Re: 1970 Johnson 60 hp coil test

Sounds to me like you need to do a Link/Sync on the motor.
 
Joined
Jul 19, 2010
Messages
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Re: 1970 Johnson 60 hp coil test

Weve ran it with the hood off once and i remember my dad bumping the face of the carbs with his hand and it didnt help. Im not sure exactly what a link and sync is?
 

rayodunne

Petty Officer 1st Class
Joined
Jul 21, 2006
Messages
224
Re: 1970 Johnson 60 hp coil test

You need a service manual for your motor. Link/Sync involves adusting the carbs and timing advance which is all covered in the manual. Check ebay.
 
Joined
Jul 19, 2010
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Re: 1970 Johnson 60 hp coil test

Is it called something else in the manual. I have one but it's hard to find stuff. It's like 3" thick. Also I took it to the water yesterday. Still has the problem but anyhow while half throttle I bumped my hand across the carbs and the bottom one is barely sucking air. I think it's an additional problem and not the problem but .... Also please tell me what is WOT mean????
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: 1970 Johnson 60 hp coil test

WOT=wide open throttle... with the throttle fully advanced, the butterflies < throttle plates in the rear throat of the carb> should be perfectly horizontal..they should move in full synchronization from closed to wot if adjusted properly
 
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