no spark, advice?

[Guest]

tried reviving my '79 gs750L from death, but it's not catching. i checked the spark plugs, and cylinders 1 and 4 aren't while 2 and 3 spark weakly. i checked the breaker points and the 2-3 sparks while the 1-4 point doesn't. any clues to fixing this? where can i check for bad connections?

[BassCliff]

Hi Mr. nidnightcafe,

A quick search turned up this thread. Maybe it will help.

http://www.thegsresources.com/_forum/showthread.php?t=128383&highlight=test+coils

This seems like a helpful post:

http://www.thegsresources.com/_forum/showpost.php?p=850580&postcount=15

Thank you for your indulgence,

BassCliff

[psyguy]

likely a bad coil or the power (or the negative) to the coils
then the igniter
or the points

[Suzuki mad]

Are you running points or electronic ignition?

Start with the battery. Tip top condition and fully charged.
Next check points, for all plastic washers and the condition of the surfaces. MAke sure they are opening at the correct time.
Check the condensors are wiring in and working correctly.
Check connectors to the coils, plug caps. Swap the leads over to see if the spark problem moves from one side to the other.

At each stage spin the engine over and check the spark.

This should identify your problem.

If you have electronic then swap the coils and see if the spark changes sides. If it does then its likely to be a coil in trouble.

Suzuki mad

[midnightcafe]

I'm running on points. Just checked the coils, both work fine. battery has a good charge, points look worked in (not quite worn down) but should work fine and open at the correct timing. i was going to take a look at the ground but it runs into the engine case cover on the clutch side, but I'll assume it's fine since the other point sparks-same ground. going to lok into the condesners, ignitor, r/r soon, just ned to pick up a voltmeter

[midnightcafe]

I read on another thread that if you see spark on a breaker point than it is not functioning properly-true, or is spark a good thing?


I picked up a voltmeter, now I'm going to check the condensers tomorrow. i was playing with the points with the ignition on and found spark through both breaker points when i touched the points together, maybe I should check the timing?

how can one check the coils with a multimeter?

[daWrench]

Same issue

I'm building a '79 GS850G and just went thru the same issue this weekend. I'm running electronic ignition pickup though but it was running on 2 an 3 only, nothing on 1 an 4. I replaced coils and all wireing to the ignition all together. Still had no fire and only 1 to 1.5 volts to that coil. It turned out to be the "ignitor box" I ended up smokeing it last night. I'm now running a heinz 57 of an ignition system but it runns like a top. Two coils from a '97 S-10 4cyl. pickup, Accel wires(build your own), MSD cdi ignition box, and a dyna electronic pickup.

[midnightcafe]

false alarm!!

So I found the problem- the points. they were dirty and not connected well, so a quick adjustment and the bike catches great on starting fluid.

a great way to test the points is to turn the ignition on and touch both breaker terminals with a flathead, then look for spark- makes diagnosing much easier. gonna get new fluids and plugs and see how it goes!