couple of questions about spark (or lack of)

[psycoreefer]

I've been trying and trying to get my carbs dialed in and I just recently went back to completely stock jetting. After going back to the stock needles I'm running way way rich on #4. This is completely new, up until now all 4 were close to the same color. I mean the plug is black and sometimes wet when I pull it. My question is could a bad spark plug wire cause this?

The reason I ask is I was sitting on it at a long red light and decided to pull the boot off the #4 plug. It made no difference at all. After that I tried pulling each of the other 3 boots and each made: 1. My idle drop way down and almost stall. 2. I got shocked through the handle bars, even though I had my gloves on. Should I be getting shocked when I pull the plug wires? Why don't I get shocked when I pull #4. Any ideas?

[randy]

You're not getting shocked on #4 because it's not firing! The plug is black and wet because it's not firing most of the time, when it does fire, the mixture is rich from NOT firing and fouls the plug. Try unscrewing the plug cap from the wire, clip off 1/4 inch of the wire and re-install the plug cap. If that doesn't fix it, the problem might be at the coil end of the wire.

[psycoreefer]

Thanks randy, I had done a search and read about clipping a little of the wire off, I'm going to try it and I'll report back. Would a pair of regular scissors work? I suppose I can try em and if they don't work I'm really not out anything, its not firing now anyways.

[randy]

real sharp ones!

[Bamper]

I'm going to try this to when I get home I have similar symptoms.

[psycoreefer]

Well clipping off a bit of the wire didn't fix it.

Just to be clear, its not possible for the coil to go bad is such a way that one plug fires and the other doesn't right? Well I didn't think so.

I guess I'll be doing the new wires in old coils trick from the tech tips. Wish me luck.

[randy]

Before you rip apart your coils, swap the #1 cap with the #4 cap. The caps can go bad.

[dbeardslee]

If you got shocked at the handlebars it sounds like there's a dead short in the wire somewhere. Are you running stock coils? If you are the problem could be up inside the high tension wires. I know when I took my factory coils off I bent the wires to stick them down in a coffee can and they broke in two - thirty year old wires and all. If you have a break on the inside of the wires where they come close to the frame I could see where it could conceivably arc to the frame and show up at the handlebars.

[randy]

Doug, I think what he meant was, he grabbed the plug wire with one hand and the handlebar with the other and got zapped. I would consider that a perfectly good coil!

[dbeardslee]

OUCH! Remind me not to do that

[psycoreefer]

What I meant was.....
I was holding the handle bars with one (gloved) hand and the rubber boot part of the spark plug wire (to unplug it) with the other.

I didn't think the spark would be strong enough to travel through the rubber boot, through my dry glove, and then through the other glove to the handle bars, but maybe it is. I can say that it was considerably less shocking (only mildly uncomfortable) then the lawn mower my aunt used to have where you had to pull the bare metal connector off the plug in order to kill it, now that would light your eyes up.

I find I tend to underestimate the power of electricity sometimes. If it is the case that the spark is that strong then I've definitely got a problem with #4 wire as it didn't shock me.

[boyat68]

Still I do not think that you could get shocked unless your hand was near the boot and there was a break in the insulation. The insulation effect of those wires are pretty robust and the spark could only jump 3/4 of an inch max. I would think that you may want to run the bike in a dark place and observe the wires to see if they are leaking through the insulation. Many of us handle the removing of the wire while the bike is running, but what the hey, maybe we are just lucky.

[dbeardslee]

Psycoreefer - So how much resistance are you rated for? Just to make sure the wire's bad don't you think you should try holding the handlebar and the wire again - but this time make sure you get video But seriously folks, if you pull the number 4 plug, reconnect the cap, and ground the side of the plug against the engine, crank it and you'll see real quick what kind of spark your getting. Don't touch anything metal on the bike with your free hand while you're doing it and you should avoid any unpleasantness.

[psycoreefer]

I had planned on doing the spark plug check when I got home and then it sliped my mind. I stoped and got new wires. All the caps test at 5k +/- .5 ohms, and they didn't have new ones in stock so I'm using new wires, old coils and old caps. I've already got the new wires in one coil, the problem coil so hopefully that will fix the issue.
I tested the coil seems how I had it out on the bench and it tests 16k oms secondary and 2.3 ohms primary. The book says primary should be 1.5 right? I guess that means a bad coil but it sure was firing #1 just fine.

[petejw]

hey psycoreefer,

still sounds like a fuel problem 2 me,
if the plug is black and sooty, the plugs been firing,
otherwise u would just have a wet plug, sounds
like the plug was firing until it got so fouled up it
stopped fireing.
to confirm spark,
pull all plugs out attach spark leads and lay plugs
on the head, crank to c if there sparking,
use new plugs, even a cleaned fouled plug may not work.
if u still have no spark on 4 swap leads with 1 as described
earlier.


let us know how u go.