cylinder 1 not firing.

[pierce]

For the past week I had popping put my right exhaust, usually only at idle. Discovered if I pull the plug on cylinder 1 it stopped.

Got on the bike yesterday. And cylinder one was not firing.

I replaced the plug wire, and cap this morning. And it still is not firing. I swapped 1 and 2, and it fired. However now 2 did not.

I am running mp08 coils from a 1500. Can they fail only on one cylinder?

It sure seems like that is the case. Am I missing something? Should I replace the coil?

[RB]

Not generally but the wiring connection at the coil could be bad..??

[gltriker]

For the past week I had popping put my right exhaust, usually only at idle. Discovered if I pull the plug on cylinder 1 it stopped.

Got on the bike yesterday. And cylinder one was not firing.

I replaced the plug wire, and cap this morning. And it still is not firing. I swapped 1 and 2, and it fired. However now 2 did not.

I am running mp08 coils from a 1500. Can they fail only on one cylinder? YES

It sure seems like that is the case. Am I missing something? Should I replace the coil? YES

[pierce]

Thank you. New coils ordered.

Hopefully this resolves the problem.

[Track T 2411]

Just curious... would this failure be found by testing the resistance from wire to wire, i.e. an open circuit?

[gltriker]

Just curious... would this failure be found by testing the resistance from wire to wire, i.e. an open circuit?

Yes. That's how I ultimately discovered the identical ignition failure mode. 3 different occurences.
I removed both replaceable plug wires from the suspected dual output ignition coil, each time, and resistance tested directly into their respective output sockets.

[warhead_71]

Wait... why did you swap 1 and 2? 1 and 4 are on the same coil. 2 and 3 are on the other.

[tlbranth]

Wait... why did you swap 1 and 2? 1 and 4 are on the same coil. 2 and 3 are on the other.

1&2 share a coil. 3 & 4 share the other.

Problem sounds to me like a bad plug.

[robin1731]

Wait... why did you swap 1 and 2? 1 and 4 are on the same coil. 2 and 3 are on the other.

tlbranth beat me to it but yeah, 1/2, 3/4. If you are looking at a Clymer manual it has it wrong. These are also different from most inline 4 engines.

.

[warhead_71]

my bad. but yes, seems like it's pretty much isolated to the wires or plug or boot if you can swap the wires and the problem moves with it. Not the coil.

[pierce]

Thanks for all the replies! I replaced the coil wire and plugs, had no effect.

That's what led me to think coil.

Still waiting on the coil s

[pierce]

Problem solved. Thanks everyone.

I replaced the coils, and that solved the problem.

[Track T 2411]

[JOLLY]

there is a resistor at the end of the plug wire that may be bad. Its inside the boot that plugs on the spark plug.

[gltriker]

Problem solved. Thanks everyone.

I replaced the coils, and that solved the problem.

Perfect.