96 Honda Shadow 1100c V-Twin

• Check for correct plugs. Probably should get new ones if you don't know.
• Correct gap.
• worn plug wires.
• Connections at boot & coil. IIRC this model has 2 plugs per cylinder.
• Make sure the plugs are wired in the correct order.
• After this, it might get expensive, coils, voltage regulator, but chances are the above will fix it.

Hi, I'm not totally sure but I seem to remember that the CB 600 series had twin coil-packs that deliver the spark to the engine spark plugs. One coil-pack will operate two of the cylinders and the other coil-pack operates the other two cylinders. These coil packs do have a habit of breaking down and the spark will not be produced for the two spark plugs that it powers. The coil-packs can be found at the opposite end of the spark plug leads, which I seem to remember are moulded into the coil-pack. You might have to change both coil-packs as I'm not sure if they are available separately, anyhow, if money is not a huge issue it would be best to change both for brand new. Be warned; second hand is not a good idea with coil-packs. while at first they may seem OK, as the coil heats up they may start to break down and cause very erratic running symptoms and misfiring (remember it's a coil and it will heat up as the electricity passes through it + the heat of the engine).
If the Coil-Packs can be separated you could swap them over and see if the problem jumps to the Nos. 3 & 4 cylinders. NB. you can't just swap the ignition leads as each lead from each pack is specific to a cylinder. You would have to swap the units and all of the wiring. Sounds complicated but it's just a matter of separating the coils from the wiring loom by disconnecting the connectors, then connecting them back up again having swapped them over.
If that doesn't prove the coil-packs are at fault, then the problem will be the CDI pick-ups. These units tell the coil when to operate to give the spark, they are generally bullet proof and if there is a problem hear, it's most likely to do with the wiring to and from them.
Good luck, Bob.

try switching the position of the two coils, the plug wires will unscrew off of the coils and that way you dont have to pull the spark plug wires too,(be sure and change the 2 wire couplers too) if your front cylinder stops firing you know its the coil, if the back cylinder still doesn't fire then your coil is good and you either have a bad #2 spark unit or a bad crank pulse generator.

Try new spark plug caps. The resisters often burn out and cause poor running off idle. On some models the caps are part of the wire and are replaced as an assembly out of the coil. To save money use genuine NGK spark plug caps (about $5 each). They simply screw on to the end of the wire. If the cap reads higher or lower than 5000 OHM's it should be replaced. The copper core spark plug wire can be purchased in bulk for $1 to $2 a foot. It can be cut to length and used as an inexpensive replacement for the stock Honda wire/cap assemblies that sell for $25 to $45 each.

Unscrew the plug boot from the wire and look at the tip of the wire if you see some blue or greenish corrosion cut off about a 1/4 inch of the wire and replace the boot on the wire Ihad that problem before on a 89 CB 750

sounds like fuel is not burning in cylinder, check for spark in that cylinder first. if no spark may need new plug, new igntion wire or new ignition coil. next check for compression in that cylinder.

Did it spark well on all the plugs? Usually if you have no change in idle with two wires removed it needs a new set of spark plug wires. If it was cylinder 2 & 3 (side by side) then you should suspect a head gasket. Does the Bronco have multiple coils or a coil pack with multiple inputs? Are these two plugs hooked up to one coil?

call honda dealer an he will tell ya over the phone. where ya get the plugs? if parts plce ask em. if wires are bad replace em.

Could be a bad pulse generator. It sends the signal from the stator to the coil.