No Spark going to plugs

[MoneyPitBoat]

I have a 1974 Mercury two stroke 115 Horse outboard motor that I can not find any mechanic to touch it. I suspect the coil or switch plate assembly maybe faulty but I am not very good with a multimeter. Does anyone have any DIY video links that I can refer to? I am in Pocatello Idaho and would like to connect with a "reliable" mechanic that could diagnose my motor problem. I would like to test the coil and the switch plate assembly while they are still on the motor rather than doing a bench test. Any advice would be appreciated. The serial number is 3762229 for the motor.

 

[racerone]

Check and see if spark comes out of the coil.

 

[MoneyPitBoat]

Thank you I will try that. If there is continuity between the the two wires coming out of the coil does that mean the coil is okay?

 

[Droid]

Not necessarily.
I assume this thing has the upside down distributor? Probably the rotor & shaft assembly. Plastic of rotor cracked & spark arcing to ground?

Like Racer said, check for spark from coil.
Remove the center wire from the CAP. Hold it near ground & crank engine. If spark, then most likely then rotor is cracked & shorting to ground.

 

[racerone]

Wires may be threaded to go into the cap.----Work carefully.

 

[Droid]

I wondered if Fond Du Lac threaded them in or not.

 

[racerone]

??????----- Parts book shows them with a brass threaded part on the cap end.

 

[Droid]

I see that now but didn't investigate that far when I posted.
TBH, I'm to the point of selectively saying no to working on these things.

Another train of thought is that these old Mercs have brittle to non existent insulation on the wires. So I would give all the wires under the cowl a close examination.

 

[MoneyPitBoat]

okay I appreciate all the info.