1968 Johnson 55hp Ignition Sys. Conversion?

tlyon

Recruit
Joined
Jun 15, 2007
Messages
2
I have a 1968 Johnson 55 hp outboard motor, model # TRL-10R. The amplifier and rectifier are not usable. The wire is beyond use on these items. I was told it is posible to convert this system to a simple coil and condenser system. I would like to know if this is true and please list the steps in doing so.

Thanks,
TRL
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

people have done it. I do not know how well it works, but the hookup is the same as a car. You need a regular 12 volt car coil and condenser as used on older cars, any brand of the 1960's vintage.

1- Connect the wire from the ignition switch (presently goes to the amplifier) to the coil (+) terminal.

2- Connect the wire from the points (also presently goes to the amplifier) to the coil (-) terminal.

3- Also connect a condenser to the same (-) terminal and mount it to something grounded.

4- Points gap is .010" with the normal setup, and critical. Don't know what to say about with a coil and cond.

Let us know how well it works. We do know that the points contacts will wear just like they did in the old cars and need regular replacement. They don't carry any significant current when operating the amplifier so wear is only mechanical in nature with the normal setup. Replacement points are getting hard to find and are expensive.
 

tlyon

Recruit
Joined
Jun 15, 2007
Messages
2
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

Thanks for your assistance..... I will keep you posted on the results

Trl
 

Tao of Funk

Seaman
Joined
Nov 8, 2007
Messages
58
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

I just finished my conversion on my 1969 55hp Evinrude. So far I'd say the results are spectacular!

That been said I haven't even had it in the water. My motor would hardly idle before and when it would idle it'd smoke like Norman Mailer and shake so hard it'd mix the white with the blue in my eyes.

I just fired it up with the new ignition system and it purred right along. I was able to idle it way back. It hardly smoked too!!!

I used an MSD Blaster 3 coil and a condenser and ballast resistor off of a Ford. I purchased all of these parts through Auto Zone (about $60 total - go look at the price for a new amplifier...). I had some 7mm spark plug wire and quick connectors laying around. That was it. The whole installation took and hour. Actually I still need to go back and "pretty it up" but it's functional. I have Boyesen reeds coming in tomorrow and I'll throw those bad boys on there for good measure.

I think this will be the end to loads of trouble I've had with this motor. I already purchased a 1976 70hp Evinrude for my next project.

I'll post again in a week after it's had some time in the water and I've gone through and readjusted all the settings. See you then!!!

GB
 

mprtech

Cadet
Joined
May 29, 2008
Messages
11
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

I'd really like as much info as you can on the subject because I have exactly the same motor, maybe some pics too? Also what are the reeds? As in reed valves? What gain might be had in replacing them? Thanks.
 

Tao of Funk

Seaman
Joined
Nov 8, 2007
Messages
58
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

Okay, I'll purdy her up, take some pics, and then post. I'm leaving town tomorrow morning for 6 days so I'm sorry you'll have to wait. Save the name of this thread and check back periodically, I'll put 'em up. Believe me if I can do it anyone can.
I was referring to reed valves, yes. The stock ones are metal and single stage (or so I'm told) and the Boyesen are two stage and part fiberglass and part aluminum. They are supposed to increase throttle response, efficiency, top end power, all the good stuff. Just go to the Boyesen website, they talk their stuff up better than I do.

GB
 

Tao of Funk

Seaman
Joined
Nov 8, 2007
Messages
58
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

More info on my conversion.

The engine idles perfectly but anytime I advance the throttle above 2000 rpm it will start to cut out. I still have the spark plugs from the CDI ignition (QL77JC4) in the boat and I am still using .010 point gaps. I have the condenser hooked to the negative (-) terminal of the coil and I wonder if I need to mount it closer to the points or one to each set of points. I will check out the former items first and see what happens.

When I find the right combination of parts and settings I will post it.

GB

P.S. Anyone know if Champion L76V plugs would be better for this system?

Do you have a point gap recommendation for the system?
 

Tao of Funk

Seaman
Joined
Nov 8, 2007
Messages
58
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

Here's some more info that only leads to unanswered questions.

I am frying the points. Dunno what to do about it. I tried widening the point gap to .020 (similar to some auto point gaps). I think I may not have the condenser hooked up properly.

I moved the location of the condenser to get it closer to the points. All of the "standard" ignition systems I have seen with points have the condensers right next to the points on the distributer plate. There are two sets of points on my 1969 55hp Evinrude and I have one condenser. I got this one at auto zone as well and have no idea if it's proper for my system. I can't place it on the distributor plate because there isn't enough room for it. I ran a wire up to the points from the condenser and made sure it shares a ground with the distributor plate as well (no luck).

What I understand about condensers is that they are just capacitors that keep voltage in the system so there isn't a second collapse of the circuit in the primary coil (causing a spark to jump right when the points open causing them to "burn". Anywho, I don't know how precise the condenser microfarad rating needs to be in my system ( 0.25 microfarad approx. I think).

I'm gonna research the condenser theory and try to distinguish a better suited condenser for my system. I'll keep you posted.

GB
 

revkab

Seaman Apprentice
Joined
Sep 14, 2007
Messages
40
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

I was thinking that the purpose of a condensor was to "build-up" a charge of electricity between discharges, giving a heftier surge of power when the spark is called for. Kind of like when you shut a garden hose nozzle off, letting the pressure build, then releasing it for a sudden surge of power.
 

trent_tweeter

Seaman
Joined
Apr 25, 2008
Messages
53
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

What were the results of your tinkering?
I'm also thinking of converting my 1968,55hp to the conventional ignition system. See thread of trent_tweeter for more reading.
Regards
 

C_hab420

Cadet
Joined
Jun 16, 2009
Messages
24
Re: 1968 Johnson 55hp Ignition Sys. Conversion?

This an old post but if anyones interested still,It sounds to me like you dont have a coil resistor since its frying points.You can pick one up for cheap at any auto parts store.Or you could buy a coil with an internal resistor for around 30 bucks.
 
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