Hello. I am not new the KLR or wrenching on machines, though I somehow am new to this site. In 15 years of owning my 03 this is the only time I've been totally confounded. I am approaching the point where I have to set this thing on fire and take it in for scrap--I just can't track this down, and these days this has become a commuting tool 60 miles to/from new york city... which means a failure to start could yield tow bill in excess of the bike's value. The problem is an intermittent hard/no start. I have been through a lot of diagnostics and believe it is spark related. All electrical components ohm out ok (exciter coil, p/u coil, primary and secondary, CDI) and the loom also ohms out (ie there is not a complete lack of continuity apparent between the corresponding ends of any circuits). I have tried a new plug, and have also swapped in a believed-and-tested-good CDI and primary coil/wire/plug cap from another KLR with no effect. The standard safety switches and the starter safety relay were eliminated 50k miles ago, the stator is stock.
If you hold the plug electrode to bare metal, it *has* spark, but it's anemic and yellow. I suspect it is an intermittent break somewhere creating either a poor connection in something that should be conducting, or a worn insulation allowing some juice to leak to ground, but careful visual inspection hasn't turned anything up. Also, my inductive timing gun can't pick up the pulse in the sparkplug wire (I discovered this while trying to confirm the timing was correct, even though I know we can't adjust it). So we DO have spark, but the spark is terrible, verging on nonexistent. Once/if the bike manages to start, it ran/runs fine, for whatever that's worth.
I bought a thing like this
...to try to objectively measure the spark strength, and I can't get it to jump at even the "small engine" setting. In fact, I have to be about 1 turn out from fully closed before the spark can gap, and you have to have your eyeball right on the thing in the dark to see it. I've of course never used it on a healthy KLR so I have no baseline, but I've seen specs for Kawi dirtbikes in the 20-30k range, so I have to believe even a lazy KLR should manage 10k, and I'm WAY under that.
I want to use jumper wires to bypass the loom and the igntion switch entirely so the CDI is in a permanent "RUN" state, and see if the spark is healthy then. I believe with all the safety crap out of the way the starter will still run, but I can jump the starter to spin the motor if I need to, I just need to confirm the ignition circuit is all wired for running.
I started here:
...which simplified down to this after skipping all the safety crap...
which is:
PICKUP COIL (2 wires) <--> CDI
EXCITER COIL (2 wires) <--> CDI
12v+ <--> CDI (B/Y wire by itself)
Chassis ground <--> CDI (B/Y and also R/B, which used to go to diode pack)
I would appreciate any confirmation that this is logical. I've read you can toast a CDI if it doesn't have correct grounding (ie you turn it over with the plug lead disconnected) and while I've definitely done that on many engines accidentally, I'd like to minimize my losses here.
Thank you.
Luke
If you hold the plug electrode to bare metal, it *has* spark, but it's anemic and yellow. I suspect it is an intermittent break somewhere creating either a poor connection in something that should be conducting, or a worn insulation allowing some juice to leak to ground, but careful visual inspection hasn't turned anything up. Also, my inductive timing gun can't pick up the pulse in the sparkplug wire (I discovered this while trying to confirm the timing was correct, even though I know we can't adjust it). So we DO have spark, but the spark is terrible, verging on nonexistent. Once/if the bike manages to start, it ran/runs fine, for whatever that's worth.
I bought a thing like this
...to try to objectively measure the spark strength, and I can't get it to jump at even the "small engine" setting. In fact, I have to be about 1 turn out from fully closed before the spark can gap, and you have to have your eyeball right on the thing in the dark to see it. I've of course never used it on a healthy KLR so I have no baseline, but I've seen specs for Kawi dirtbikes in the 20-30k range, so I have to believe even a lazy KLR should manage 10k, and I'm WAY under that.
I want to use jumper wires to bypass the loom and the igntion switch entirely so the CDI is in a permanent "RUN" state, and see if the spark is healthy then. I believe with all the safety crap out of the way the starter will still run, but I can jump the starter to spin the motor if I need to, I just need to confirm the ignition circuit is all wired for running.
I started here:
...which simplified down to this after skipping all the safety crap...
which is:
PICKUP COIL (2 wires) <--> CDI
EXCITER COIL (2 wires) <--> CDI
12v+ <--> CDI (B/Y wire by itself)
Chassis ground <--> CDI (B/Y and also R/B, which used to go to diode pack)
I would appreciate any confirmation that this is logical. I've read you can toast a CDI if it doesn't have correct grounding (ie you turn it over with the plug lead disconnected) and while I've definitely done that on many engines accidentally, I'd like to minimize my losses here.
Thank you.
Luke