78 GS550 No Spark? Where to start troubleshooting?

[ilyena]

Hey yall,

I have a 1978 GS550 I picked up a few years back.

Ive upgraded/replaced a bunch of things on the bike, (generally once it stops working!) and recently replaced the stock gauges with aftermarket.

However, when I went back to start the bike up after wiring the new gauges in, she won't start. She won't kick. I have no spark at the plugs.

I replaced the points and condensers with a Dyna S ignition. I replaced the rotor with a Rick's rotor, replaced the regulator/rectifier with a single R/R unit. About the only thing I haven't replaced is the coils, and the starter relay. Both were in great working order before doing this wiring. I figure the coils wont simultaneously go bad. Unless I really ****ed something up.

When I hit the starter, the relay clicks and the motor tries to start, but never catches (again, no spark). I have compression, I have gas, and air filter is clean.

Ive tried digging into the Clymer manual with the signal generator/igniter troubleshooting but I'm totally lost. Are those the electronic ignition? If not, what are they? Is the troubleshooting even the same? All my wires are different colors than the ones the manual says, and it seems very particular about which wires to connect to what.

I'm assuming I ****ed something up when I wired in the gauges, but I have no idea what. I just ripped out and rebuilt the wiring harness to eliminate the possibility of any of that being bad, and still no dice. I'm hoping I didn't fry the electronic ignition.

Does anyone one have any idea of where to start? How can I narrow down what the issue is? Is there a good guide anywhere, or a good checklist/flow chart?
Let me know if you want more info.

Thanks in advance,

 

[mvalenti]

do you have voltage to the coils?

 

[ilyena]

do you have voltage to the coils?

Whats the best way to check this?
I don't have voltage resting, and when I hit the starter I have low voltage, like 0.6V. This was before rebuilding the harbess though. I can check again when I get home.

 

[mvalenti]

Test the voltage to the coils with a voltage tester. do you get 12 volts at the coils? Orange wires..

 

[ilyena]

Test the voltage to the coils with a voltage tester. do you get 12 volts at the coils? Orange wires..

Should I have 12 volts with just the bike on? Or just when I try to start?

 

[cowboyup3371]

What voltage is your battery sitting at without anything on?

 

[ilyena]

What voltage is your battery sitting at without anything on?

My battery is a little weak, but ta just over 12V.

I think I may have resolved the problem!

I wasn't getting a readings at the coils, so I went back and traced wires. Something was funky at the handlebar switch, so I pulled off the aftermarket one and put back on the stock.

I have spark now!! Yay!

Now I just need to put everything back together and hope it still works
Thanks for the help guys, I'll come back if I continue to have issues.