1972 Mercury 500 50 HP

[racerone]

Some will argue.------Stop trying to start this motor by guessing.-----Remove the bottom half of the magneto ( 4 screws ) and test for spark on your work bench.----Clean and set breaker points at 0.010".----If no spark repair as needed.-----Then install the proper ignition switch and wiring to run this motor.

 

[64Amphicar]

So I have the Orange wire coming from the Magneto thru the wiring harness to the E terminal on the Ignition switch. This needs to be grounded at the Ignition switch??

 

[64Amphicar]

Some will argue.------Stop trying to start this motor by guessing.-----Remove the bottom half of the magneto ( 4 screws ) and test for spark on your work bench.----Clean and set breaker points at 0.010".----If no spark repair as needed.-----Then install the proper ignition switch and wiring to run this motor.

I have the correct wiring harness for this engine, the problem I am having is the ignition switch connections. What is the proper ignition switch for this engine??

 

[racerone]

Last try.----E to D should be OPEN to run.----E to D should be closed to stop motor.----Your local shop could check the operation of the key and terminals and verify it's application for a magneto.

 

[GA_Boater]

I was given this pontoon with this engine mounted on it. It had an Evinrude 40hp on it before.

You have an OMC key switch, that's why the markings on the switch don't match for a Mercury outboard.

 

[64Amphicar]

You have an OMC key switch, that's why the markings on the switch don't match for a Mercury outboard.

Will this switch work or will I need to find one for a Mercury Engine? I now realize why he gave me this pontoon, but if I can get it going it will be great for the grandkids!! Sorry dealing with al my questions. Thank You

 

[racerone]

I give up.-----Switches are so easy but difficult to explain to some folks ----Sorry to be so blunt.

 

[merc850]

I can't watch!

 

[64Amphicar]

Some will argue.------Stop trying to start this motor by guessing.-----Remove the bottom half of the magneto ( 4 screws ) and test for spark on your work bench.----Clean and set breaker points at 0.010".----If no spark repair as needed.-----Then install the proper ignition switch and wiring to run this motor.

I have removed the Magneto and replaced the breaker points, put on new rotor and new plug wires. Have spark from the terminal on the side, but no spark from plug wires. These are new 7mm plug wires. Any advice??

 

[racerone]

What kind of plug wires.----Solid wire core ?----Automotive wires ?

 

[64Amphicar]

What kind of plug wires.----Solid wire core ?----Automotive wires ?

Marine wire set- silicone, I was told they were correct, old ones were wire.

 

[racerone]

Should be wire core I think.

 

[64Amphicar]

Should be wire core I think.

Found out that this is a 1966 Mercury 500 50 hp with the magneto. I have replace the spark plug wire with the correct wire core plug set, new rotor, new breaker points and new spark plugs. Still no spark at the spark plugs. Could it be the rectifier and or condenser?

 

[racerone]

Rectifier has nothing to do with spark.----Battery is not involved with making spark.----Test this magneto before you install it on the motor.