Strange Ignition Wiring

Bought a '81 9.8 hp Mercury I've been fixing up. It's getting close to running how it should but I still have one problem.

The motor runs fine at idle to half throttle. If I give it much past half, it dies on me and is difficult to restart (requires starter fluid). I haven't pulled the plugs and looked at them when I've been on the water, but based on looking at the plugs after running it in a bucket, one of the plugs seems to foul slightly. One of my friends said it sounded as if I was having weak spark. i.e. the spark is enough to fully combust the fuel that is delivered at lower throttles but when you open it up, it floods it out.

I'm trying to take a look at my ignition system, but it seems really strange (see attached photo). It looks like each cylinder is fired by a completely separate coil. The ignition wire running from "Coil A (Right)" to "Cylinder A" just barly makes contact with "Coil A (Right)". I looked inside where the wire plugs into "Coil A *" and it is just a flat piece of metal in there (Nothing for the ignition wire to mate with).

Can anyone tell me if this ignition system is wired correctly? How to test if the spark is strong enough? Or direct me to good resources to learn about these types of ignition systems?

Re: Strange Ignition Wiring

No, it's not correct and has incorrect parts. If you need a wiring diagram give a serial number

Re: Strange Ignition Wiring

A wiring diagram would be great. serial #5640936. Thanks for the info.

Re: Strange Ignition Wiring

It should be a 1980/81 engine

Re: Strange Ignition Wiring

That's great thanks. So I have no idea what "Coil B" is then but I'll try wiring it through "Coil A (Left)" (which I should now call "Coil 2"). Before I switch cyl 2 over to the "Coil A (Left)" do you know what the impedance should be of the coil? All three coils are currently around 0.3 ohms. The thing that still concerns me is how the high tension cables (formally "ignition wires") are connected to the coils. Is it really only suppose to butt up against each other without actually mating?

Re: Strange Ignition Wiring

(Double post)

Re: Strange Ignition Wiring

Primary side------Rx1------.02.04
Secondary side---Rx100---9-12
Or just swap your input wires coil to coil nd see it the problem moves coil to coil

Re: Strange Ignition Wiring

The coil B looks to be for a Johnson motor and is not correct for your motor. Someone has cut the wire for the coil that is not hooked up and added coil B. Coil left A should have a screw in the plug wire hole that the wire screws onto and makes a good conection. Both A coils should be the same and the plug wires should be ones with wire cores and not the newer carbon grafite core. The motor is not running correct because of this diffrence. You will need to replace the coils an wires, if not as stated. You have to have a good ground wire from the block to the coils on the coils you have on that motor. Some older coils had the ground wire on the back surface and grounded the coil when it was mounted inplace.
Oldman570

Re: Strange Ignition Wiring

Thanks for the direction Laddies and Oldman570. I won't be able to work on it for a week or two but when I do I'll post the results for future readers.