lack of spark

[Guest]

hello guys just a quick question 1980 gs750g . had carb troubles a while ago it ran but a bit crappy ,so put correct carbs on after 3 weeks of standing now ive not got any spark on 1/ 2 /4 .it has one of the dyna electronic ignitions on any info on tests .if it aint one thing its another trying to keep the old bikes on the roads instead of the scrap yards

[tom203]

Make sure you didn't break a connection somewhere on dyna to ignition coils..... Read/follow this link

http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17

[Brendan W]

I've got a Piranha system with stock coils. I lost sparks due to one of the coil plugs being dirtier than the other and the plug to the Piranha box was also dirty and loose. Wiggling the harness picked it up.

[60ratrod]

no spark on #2 could be a bad wire. you should do a couple tests here with the ignition since you have the dyna s setup. do you have the dyna coils as well? I've had 2 dyna coils drop one side of the coil, which could also be why you don't have spark on #2, since 2 & 3 are fed off of the same coil. so what you are going to need is a multimeter.

reading on ohms, you should see about 3-4 ohms on the wiring harness threaded connectors, and 12,000-14,000 ohms through where the spark plug wires connect if you have dyna coils.

if those check out ok, I would look to see what you are getting for voltage at the coils where they screw into the coils. the o/w should be reading 12vdc, the signal wires which should be black and the other white, both in the harness and from the dyna, you should be seeing .8-1.4 vdc when the rotor magnet is not facing either pulser coil. if you are seeing less than 12vdc on the o/w wire, you are experiencing a common problem with voltage drop, some of it probably induced by the dyna s.

if the o/w is good, and you are seeing less than .8vdc on the signal wires, there's a good chance that you have a problem with the pulser coils on the dyna s. loosen the small allen head screws and lift the plusers off of the dyna plate, but make sure to mark where they were set before you lift them. then put them back on the plate and recheck for vdc. did it come back? no? then the dyna is toast.