1971 Johnson 50 hp Ignition and Throttle Cable Question

TruckDrivingFool

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New to me boat has a 1971 50hp Johnson. I'm searching for a manual now but until I can get one I have a few questions:

1. It needs a new throttle cable, I know I still need to measure for the length but I'd just like to verify that the Johnson-Type-400-Control-Cable is the correct cable before I order.

2. I know on my 115 of the same era the ignition runs off the battery and not a magneto, does the 50 run the same way? I ask because I didn't think about today in the purchase process when the PO said that it ran the battery down. After looking at the parts list and seeing only a stator and no magneto it clicked that maybe I need to pay attention to the charging system before I get this back on the water.
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

How about just some help on the cable? I'm itching to get some parts ordered.
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Will pics help?

The box style

02SCThrottle.jpg


The end that goes to the box

02SCThrottleCable01.jpg


The motor end

02SCThrottleCable02.jpg
 

bernd64

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

at the end of the cable is the length sempt on it and you can get some teleflex cables to
 

jay_merrill

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

You need a type 400 cable, not a Type 479. The type 479 would work on the motor, but it is not compatible with the control box.

Your motor has a magneto CD ignition, not a battery CD ignition, like your other motor. That is good news, because the Magneto CD systems is better and easier to get parts for. If you have to replace any ignition parts, I recommend Sierra and CDI parts - they are about half the price of BRP parts, which are house brand, aftermarket parts anyway.

You should be able to get whatever you need, right here at iboats.
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Thanks guys,

Yes it is good news, I noticed that many more of the parts are available for this motor and they're cheaper.

Once I get the motor back on the boat (replacing transom board) Is there a quick test I can do to check that the charging system is working?

Still looking for a service manual so anyone knows of one I'd like to hear of it.
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Found an Evi manual that should be close enough right?
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Alright I've got the transom board and throttle cable done. Hope to run it on a hose tomorrow after changing the impeller and LU oil.

I'm still waiting for the manual to show and would really like to know if a simple voltage check or something similar will show if its charging.
 

lmuss53

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Once it's running put a volt meter across the battery posts, it should show 13+ volts if it's charging. I don't think there is a regulator on it so keep a big battery for cranking. 14 and 15 volt readings are not unusual and the battery has to be able to absorb the juice. On long runs you might have to turn on some accesories to take some of the charge out of the battery. I have a battery combiner I am putting on mine to transfer the charge to the trolling battery if the cranking battery gets above 13.5V.

If it isn't charging check the rectifier first and then the stator. Do a search in FAQ for rectifier test. If you get to the stator check the CDI sight for specs on your model.
 

TruckDrivingFool

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Re: 1971 Johnson 50 hp Ignition and Throttle Cable Question

Thanks Imuss,

I got my manual Monday, changed the impeller and fluid, and tried the rectifier and stator tests. However with the heat I was wiped out so I didn't have a chance to run it. The manual confuses me a bit since it lists high and low meter settings and I'm using a modern digital meter. I think the rectifier is ok as I tested per the manual and got a reading one way and nothing w/ the probes reversed. The stator I was more confused on since they said 1.5ohm was normal +- 5. I got right about one so I think its ok but not sure. When I get back to it this weekend now I'll be able to check the voltage and see if I need to look harder.
 
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