Re: 89 Force 125 coil questions
If it's firing normally on all four cylinders, when you pull a spark plug wire off, it should change the idle speed and run a little rougher. Just keep in mind that there is more than just ignition spark that will prevent a cylinder from operating correctly. Rings have to be in good shape for proper compression, reed valves and carburetors have to also be operating properly. Check compression first and see what your readings are. Readings should be within 10% from highest reading cylinder to lowest cylinder.
If compression is OK, take some stator resistance readings. You should read between 680 - 850 OHMS between the two sets of Blue and Yellow stator wires. Reading between both sets of wires should be very close to the same. If you have 1 set that reads 700 OHMS, the other set should also read the same.
If stator readings are OK, then take a look at all the spade lug connectors on the 12 position terminal block. Right at the spade lug connector on the end of each wire, there is sometimes a small piece of black heat shrink that covers the spade lug connector itself and the wire. Sometimes the strands of wire break inside the heat shrink and you cannot tell.
If the spade lug connections are OK, then you might try swapping the CD Modules around to see if the "symptom" moves to number 3 and 4 cylinder. Note, take very careful notes, maybe digital pictures of the wires. It's very easy to get things mis-wired and really create a major headache in trying to put things back to the way they're supposed to be.
