Testing for Faulty Ignition Coil

[Cactus Bob]

My '04 GS is starting to misfire under load or hard acceleration - starting, idle and cruising seem OK although engine doesn't run quite as silky when hot as it once did.
Anyone know how to test for a faulty ignition coil?

[MCMULLAN]

Originally Posted by Cactus Bob

My '04 GS is starting to misfire under load or hard acceleration - starting, idle and cruising seem OK although engine doesn't run quite as silky when hot as it once did.
Anyone know how to test for a faulty ignition coil?

Thats weid...my 04 has a light surge at around 3500 on the fwy

i've always wondered if it's a coil.

[marc]

Originally Posted by Cactus Bob

My '04 GS is starting to misfire under load or hard acceleration - starting, idle and cruising seem OK although engine doesn't run quite as silky when hot as it once did.
Anyone know how to test for a faulty ignition coil?

When the bike starts acting up pull the input to each coil one at a time. If, when you pull one, the bike doesn't get worse you've found the bad one. That might not help if the problem is intermittent. Got a friend with a GS? You can swap coils one at a time. They're a bit too expensive to just buy a replacmemt, especially since there are 3 different part numbers. The primary coil will fit left or right, but the secondary coils are different for each side.

Also, check your plugs. If they're close to the 24K swap mileage swap them even if they look good. New plugs have been known to fix stumbling under load conditions.

[Cactus Bob]

Thanks for the feedback Marc.
Yeah, the problem is intermittent at this point and I was hoping for a magic diagnostic solution. I've got some Denso Iridium plugs on order already so I'll wait to see how that effects things. Now if only Canada Post could solve their labour issues. The plugs are stuck somewhere between California and BC.

[Cactus Bob]

Originally Posted by MCMULLAN

Thats weid...my 04 has a light surge at around 3500 on the fwy

i've always wondered if it's a coil.

In searching around about my misfiring problem I ran into a few posts that connected surging to plugs ... but if that's true then the coil could easily be another culprit. I'm thinking that a light surge would more likely be the secondary coil or plug, but that's more a guess than anything.

[pdxrmccgs]

If I recall correctly some flavors of the K-bikes had surging issues. You
might pop over to their forums and see what their thinking is.