1997 mercury 115 hp

[Johnson110]

I am looking for the switch box on this engine and I only see ignition coils going to the plugs. Does this model: 115 explto serial: OG485647, have a switch box? I read that some only use the stator wires going to the coils.

 

[Chris1956]

The later 1997 models like yours have CDM ignition. In effect, each coil is a combo switchbox/coil. They are connected directly to the stator.

 

[Johnson110]

Ok that makes sense, the motor was running perfect it now has a miss and running rough after warmed up and going down canal. I am going to hook up spark tester the one you can run in series with the engine running to see which cylinder is cutting out. I am thinking it is one of the top cylinders as it seems to not do it when engine is running when all cylinders are firing. It has a red stator under the flywheel I read they can be problems.

 

[Johnson110]

I switched the coil with the bottom cylinder and started it up and went back to running good. The coil has a male female plug on it. I am pretty sure it is the coil, Can they go bad after engine is hot?

 

[flyingscott]

I switched the coil with the bottom cylinder and started it up and went back to running good. The coil has a male female plug on it. I am pretty sure it is the coil, Can they go bad after engine is hot?

That is usually when they start to act up when they get warm. Stay away from the inline spark testers. Get one that has an actual adjustable air gap

 

[Texasmark]

I switched the coil with the bottom cylinder and started it up and went back to running good. The coil has a male female plug on it. I am pretty sure it is the coil, Can they go bad after engine is hot?

I had temp problems with a CDM on a 2002 90 hp so yes they can and will. Might get some white thermal transfer grease and put it on the bottom of your module before you mount it to the plate and do it to all of them while you are at it. While you are at it, do the same thing to your rect/regulator module....internet has it if local auto parts store doesn't.

 

[Johnson110]

Yes that is a good idea with the thermal grease, so you have a bad CDM coil?