Re: 1970 johnson 60 hp msd ignition or other options
because after reading a whole lot of threads , i am a little worried about the amplifier longevity in this model motor. and have read about people going through the 300.00 plus part all the time. so i would like to upgrade the motor so to speak for better performance and reliability.I mean in reality i don't want to buy a new amplifier have it working great then be out on the water trolling with my other motor and having a fishfinder running all day and then realize after i try to start the big motor that my battery voltage has dropped to below 10 and i just blew another amplifier. if there wasn't a problem with this particular system there wouldn't be so many threads with people trying to rectify the problem. it also worries me that you also could have problems just by using a deep cycle battery. CONVERSION TO MSD IGNITION:
The benefits of running the MSD 6A ignition in place of the factory CDI ignition used in 1967-71 are numerous.
1) The MSD box is more durable. MSD boxes work with as little as 5 volts or as much as 18 volts. Factory box will quit working if charging system is faulty.
2) Factory box sparks one time while MSD ignition box sparks through 20 degrees of crank rotation.
3) MSD box is much cheaper than factory box and MSD box can be purchased from most auto parts stores. Factory boxes are becoming harder to find, as they are no longer in production.
4) An outboard with the MSD box is much easier starting, idles better, and has improved throttle response.
PARTS REQUIRED:
A MSD 6A ignition box and (2) high vibration coils. The coils need to be high vibration, as oil filled will break down from the engine vibrations. The 6A box is currently offered on summitracing.com for $179.00 and the coils are $40 a piece. Total parts cost= $260.00. Cost of a factory box is $250 to $350.
INSTALLATION:
The installation is very straightforward. Follow installation instructions per MSD standard ignition hook up. Heavy red and heavy black wires to 12v positive and 12v ground. Thinner red wire connects to a 12v switched power source. Now here is where this gets a little interesting. The orange and black wires connect to the coil; orange is positive and black negative. However, these wires need to be spliced so that both coils can be hooked up. One coil is connected to the distributor cap and the other coil has its coil wire grounded directly to the block. The reason for this is simple: The MSD ignition produces approximately 45,000 volts. The old system puts out 30,000 volts. The distributor cap will not handle the extra voltage so the 2nd coil is wired in and by grounding it out, the MSD voltage has been cut in half to approximately 22,500 volts. Finally the white wire is connected to the points under the cap. That completes the installation wiring. The MSD box can be mounted directly to the motor or it can be mounted in the boat somewhere. The installer will have to figure out the best locations for both coils to mount as well.
FINAL THOUGHTS:
By upgrading to the MSD system, the motor will perform well for many years to come. The MSD system dramatically improves the overall performance of these motors. The MSD box must be a 6A. MSD offers some less expensive ignition modules but they do not work. The box has to be a true CDI unit. Also, the MSD box will work on any 4, 6, or 8 cylinder 4-stroke engine. However, it will also work on 2 stroke outboards with 4 cylinders and it should also work on 3 cylinder models as well. The author has only used the MSD system on a V4 Johnson 85hp 1970 outboard. It worked great!!
Occasionally the other method of converting these motors to standard 12v inductive ignition is offered as an alternative to the CDI ignition. This conversion is done by adding a condenser and a ballast resistor to the ignition system and using the coil to store up the ignition energy. I have never done this conversion personally but I have been told it would work. However, there is one problem that occurs with this conversion. When this method is used it will directly cause much more wear and tear on the points. This is because when the CDI system is not used more voltage goes through the points, which shortens their lifespan. These points are no longer available and they are harder and harder to find. So, this should be considered when deciding which conversion to use.
