No Spark from 1 and 4

[Guest]

I'm topping out at 75mph with my 1978 GS750E (bobbed with pod filters, aftermarket 4 exhuast pipes). All of the plugs are fouling, and my #1 ( under a petcock that leaks on RES) is wet fouling. The points timing has been adjusted. I've recently changed plugs (b8ES to b7ES) and found that 1 and 4 have faint amber to no spark.

Should I be checking the coils? What should I look for? My battery connection is intact. Should I test the battery itself?

[tom203]

Yeah, test electrical system (i.e.,charging system) to rule it out and go from there; head to this link and report the 6 results of the quick test

http://www.thegsresources.com/_forum/showthread.php?p=1272192#post1272192

[tedwoodstrong]

Yeah, test electrical system (i.e.,charging system) to rule it out and go from there; head to this link and report the 6 results of the quick test

http://www.thegsresources.com/_forum...92#post1272192

Thanks for replying. My multimeter readings were as follows:

Key off - 12.5

Key on with lights for 10 secs - 12.14

Idle - 12.19

2500 rpm - 12.6 - 12.7

5000 rpm - 13.01

Key off - 12.5

I should add that the #1 plug has little to no spark, #4 has a very faint spark, while #2 and #3 have weak amber spark.

[tom203]

You have some charging, but it's pitiful- so you got work to do there. But unless your ignition circuit connections are real bad, this doesn't account for your weak spark. Remove tank and measure voltage at coils. With ignition on, you want it close to battery voltage.
You might want to get new condensers and points.