[raisin75]

I have spent quite a bit of time diagnosing my '75 GL1000 project for starting issues, as well as an issue with voltage drop back to the voltage regulator, which I believe is causing an overcharge.

If I have 13 volts at the battery, I will only have 11.5 or so on the black wire coming back from the ignition switch. I have checked the ignition switch and it is ok. I also jumpered it directly just to be sure. I have a very low resistance from the black wire to ground. I noticed that if I turn the kill switch to stop, the resistance to ground increases substantially. I understand that I should still have a fairly low resistance due to lighting and such, but the kill switch seems to have the biggest effect. To prove this, my starter turns the engine over easily with the kill switch off, but when the kill switch is in the run position, it barely turns the engine.

If the starter does turn the engine, it will start easily and run fine. I'm a little stumped and looking for help to see where to look. Since it runs well, I would think the coils, points and condesors are ok, but maybe not.

I think if I can track down this issue, it will resolve my starting issue as well as the overcharge caused from the voltage drop. Any help is greatly appreciated.

 

[raisin75]

Faulty ignition timing. Back in my day you could advance the ign timing via the distributor so far that the engine would barely turn over.

I was considering that ignition system could be causing something, but have not even checked the points system yet. I will get in there when I get home and see where everything is, then clean and set the gap for the points before putting a timing light on it.

As for the battery, it is a non-issue as I have done this using my 4runner battery even while the 4runner is running, so plenty of juice getting to the bike.

 

[raisin75]

1) The low voltage to the regulator on the black wire is definitely causing your overcharge concern. With engine running, apply battery voltage to the black wire at the regulator, and watch your battery voltage decrease to normal levels. There is a fix for that.

What is the fix for this? As I stated earlier, the ignition switch has good continuity, so I'm not sure where else I would be losing voltage. I thought it might be in the ignition circuit, but now you all have me second guessing that. I do need to check all of the grounds.

 

[raisin75]

Working on timing

I have been working on the old girl for the last 2 nights while the family is out of town. I have made some progress, but not quite where I wanted to be. I adjusted the valves, put on new valve cover gaskets, changed the oil, and cleaned the grounds. Now I am working on the timing. Wow! I never thought it would be this tedious. I am using the static method and realizing that as I adjust one thing it affects another and on and on...

I did get it started last night and the starter seems to be working much easier. It appeared that one of the points was grounding out against one of the screws on the plate. That with the adjustment of the timing seems to be helping with the starting issue. I will continue to work on getting the timing set tonight and report back any findings as I continue.

I should be just a few days from having this old girl back on the road!

 

[raisin75]

Solved!

Finally found the issue that was causing all of my timing woes. I pulled the points plate, and found the mechanical advance was stuck open. Lubed it with PB Blaster and worked it quite a bit and it loosened up nicely. Put the points back on, set the gap, static timed and fired right up.

Also, I believe I must have had a short in the points, because my charging and starting issues seem to be resolved as well. The voltage to the battery did not get over 14 volts and was typically around 13.5-13.8 volts while running.

I'm definitely in better spirits tonight than last night. Thanks to all for the help pointing me in the right direction.