1981 GS550L Dyna S Coil Voltage Drop - Bike Doesn't Start

[kylekochan]

I recently installed a Dyna S ignition and cleaned the carburetors.

Here are the things I've tried.

1) I've connected the red wire from the Dyna S to the white/orange wires leading to the coils but find the voltage drops from over 12V at the battery and coils to under 10V.
2) Therefore I decided to connect it to the headlight orange wire instead, where the voltage only drops to 11V at the headlight and at the red Dyna S wire and still cannot get the bike to start.
3) I then have tried to connect the red wire to the battery directly temporarily and get some spark but the coils drop to a voltage under 10V and the bike still does not start.

Edit: I'm new to all of this. I just noticed that my spark plugs are dry but my carburetors have fuel in them. Why is there no fuel getting to the plugs?

What is a good next step?

Thanks!

 

[salty_monk]

What's the history of this bike?

Probably not what you want to hear but you likely need to go through the harness and clean all of the connectors. Check for bad grounds. Possibly fit a switched relay to run power to the Dyna S and coils directly. That way you'll get battery voltage. Use the orange white to switch the relay.

I will say however that even with those losses most GS's will run.

I would say your problem may relate to the carbs. Have they been cleaned? All O rings replaced etc. There is a Newbie thread you should look at...

Welcome to the mad house

 

[kylekochan]

Thanks for the welcome! This forum has been very helpful so far.

I've owned the bike for about 9 months now, was running for a few months until the winter when the throttle cable snapped (first bike so didn't really know about lubing the cable, I've learned a lot since then, still a lot to learn) so decided to store it for the winter. Took the tank and other parts off the bike to paint over the winter as a project so I had the carburetors drained and left over the winter until I rebuilt them last week.

I recently did the following:
-Dyna S Ignition
-Cleaned and rebuilt the carburetors (rebuild kit and carb dip)
-New Tires, Brake Pads, Chain, Sprockets, Air Filter, Oil (Rotella 15w-40) and filter, new throttle cable, spark plugs, filter box boots, and intake boots
-Bled the brakes, lubed the throttle, clutch, and choke cables, weather stripped the air box

Still need to:
-Check the valve clearances (waiting for feeler gauges)
-Synch the carbs
-Maybe some other things I'm missing

So essentially I haven't had the bike running since November but the only things I've changed that I believe would be an issue is the Dyna S, Carburetors, Spark Plugs? I've had the battery on a tender all winter. Reads above 12.6V. Don't believe the valve clearances would be an issue especially if the bike had been running fine and left since.

The carburetors have fuel in them and I bought rebuild kits so I believe they're fine, new o-rings and everything (the PO stripped most of the jets so decided to buy rebuilds), the spark plugs are dry but do provide spark and I did the static timing for the Dyna S.

Little late to try anything right now but I have an auxiliary bottle of gasoline feeding the carburetors directly. Do I need to shut off the vacuum tube from the carburetors? Assuming even if my Dyna S isn't working, the engine is turning over and my carburetors have fuel, so the spark plugs should at least be wet with gasoline correct?