"91" Gsx1100G spark problem resolved, not fixed

[rphillips]

Bike running & starting perfectly, then it sat for appx. a month, then would not start, would not even try to hit a lick, no sputter, pop, backfire, nor nothing, cranked fine just wouldn't hit. Removed the old plugs, NGK JR9B that have been running fine for a few yrs., & installed a new set. Same thing, not even a pop. Then put in a set of used NGK D9EA (non resistor), from my GS1100E & after appx. 3 sec. of cranking it fired right up & purrred like a kitten. Been starting & riding it here locally for a couple of days & all seems perfect. I didn't fix the orig. problem that caused the "R" plugs to not fire, but for now, it is resolved. Also checked coil V again, with ign. on coil shows 10.6 V, when eng is running coil shows 12.4 V. I've not a clue...???

[LAB3]

I'll leave the coil voltage question to someone else but my first impression would be that the gas evaporated out of the float bowls. Did you put the petcock into the "prime" position before starting? Perhaps you did when you swapped plugs but didn't remember doing it....

[rphillips]

Good thought, but no. My first thought was fuel related so checked all the fueling stuff first, these GSX1100G's are fueled by an elect fuel pump so no "pri." setting available, all fuel related working properly. Then checked spark at plug 4 & there was none. That's when I started digging into the elect. end. Seems strange.

[earlfor]

Bike running & starting perfectly, then it sat for appx. a month, then would not start, would not even try to hit a lick, no sputter, pop, backfire, nor nothing, cranked fine just wouldn't hit. Removed the old plugs, NGK JR9B that have been running fine for a few yrs., & installed a new set. Same thing, not even a pop. Then put in a set of used NGK D9EA (non resistor), from my GS1100E & after appx. 3 sec. of cranking it fired right up & purrred like a kitten. Been starting & riding it here locally for a couple of days & all seems perfect. I didn't fix the orig. problem that caused the "R" plugs to not fire, but for now, it is resolved. Also checked coil V again, with ign. on coil shows 10.6 V, when eng is running coil shows 12.4 V. I've not a clue...???

10.6 volts is a dead battery. Check voltage at the battery terminals engine off. It should be between 12.5 and 12.85. Check voltage at the coil terminals engine off and ignition on to see what your line drop is.

Probably should charge battery also and then make the checks again.

[rphillips]

Batt checked good during time I was trying to figure things out, did leave charger on it a couple of nights while working on it. Also I did have a jump wire on coil +, to check coil V. Checked it after got running & it shows 12.4 to 12.5, turn eng. off & key on, still 10.6 to 10.7, eng fires then back up to 12.4 or 5.

[earlfor]

Batt checked good during time I was trying to figure things out, did leave charger on it a couple of nights while working on it. Also I did have a jump wire on coil +, to check coil V. Checked it after got running & it shows 12.4 to 12.5, turn eng. off & key on, still 10.6 to 10.7, eng fires then back up to 12.4 or 5.

If it shows 12.5 and when you turn the key on, it shows 10.6, you have a bad battery.

[rphillips]

I wish I could remember all the different readings & tests I did. I don't remember while I had the V meter hooked to the coil + I don't think I hit the starter to see how much the 10.7 dropped. I do remember while the V meter was on the batt. it was at like 12.7 & I hit the start & it dropped to like 12.4. What really caught my attention, I hooked a jump wire from the coil + direct to the batt. while looking at the sparkplug & cranking the eng. there was a much brighter bluer spark than I had seen before the jump wire. At that time the non resister plug was hooked up. I immediately put the new JR9B in the plug cap & cranked the eng. again. I saw a barely visible weak intermittent spark. Before the jump wire was hooked in the D9EA plug had a spark but barely visible, the JR9B had no visible spark. Now the JR9B has a very faint intermittent spark & the D9EA has a normal looking blue spark. Right then I installed a complete set of the D9EA's , hit the start button & in appx 3 sec. the thing fired right up. Disconnected the jump wire & with V meter still showing 10.7 at coil, the thing fires up perfect every time. Keep thinking what else I've done but the change from the JR9B plugs to the D9EA is it. As much as I've cranked, afraid I was going to mess up the starter trying to get it to hit, then recharging a few different times I wouldn't think the batt could have been it, but sure doesn't seem right the switch from resistor plugs to non resistor could be it either. Just happy all seems fine now, except still the 10.7 V at the coil. Like title says resolved not fixed.