The Laws of Probability

[bohdan]

Gents, I think I pretty much determined that my issue is ignition related. It happens intermittently and is therefore hard to diagnose. It is happening more frequently now and I guess I have to start changing some ignition parts. On the occasion that "Big Red" doesn't start there is backfiring in the exhaust and also asi if it wants to start but like a whimper in the exhausts. Since this has happened before, I can only figure it is a timing issue. I do know that I have spark.
So since this is intermittent, I think the only choice I have is to start switching parts that is ignition related. Starting with the most probable. I don't have my diagram in front of me, but the parts, ECU, coils, spark plug wires, Pulse generators, TW and TE and gear shift(?). From memory. WHich would be most likely the culprit? If the ECU, I guess my only option is used? Mighty Obliged.

[XJSRider]

Hi Bohdan,

Your profile says you have a gl1000 but this is posted in the gl1500 forum, maybe a misspost? If not...

Do you have factory service manual for the bike? There is a procedure in there under the coil section where you test sparkplug boot to sparkplug boot, through the coil, with ohm meter, resistance should be (by memory) around 24k ohms.

Front most two cylinders share a coil, middle share, and rear share. It is a long way to reach so you might need some help. Hope this helps.

[bohdan]

Hey XJS. Yeah, got a few GW’s. This is for a 1993 GL1500. If I did my detective work right, I can’t see all three coils failing at the same time. If one coil did, I would think it would at least fire on 4 cylinders, albeit rough. Yes?

[XJSRider]

That's true, but the simple resistance test can isolate which leg of the ignition system has the problem... at least for plug boot resistor/wire/coils.

If sporadic it may not show up, maybe a loose connection.

[DenverWinger]

You might check the connections at the kill switch, I understand they are screw terminals with lugs on the wires and sometimes work loose. That could cause intermittent spark. The '93 will still crank with kill switch "off".