Coil problem 2 stroke experts? Now with pics!

I picked up my 71 g3ss last night and now it's time to work on it. It has no spark. I looked up some stuff and it looks like it has an ignition coil and a lightning coil. It's also a 6 volt system. Anyone have any idea how to tell which coil is bad? Also a guy on another site said to use a 3 ohm aftermarket coil. I'm just not sure if it's ok to use a dyna 3 ohm with a 6 volt system. I hope I can cuz the oem ones are nowhere to be found. I'll post some pics maybe tonight or tomorrow for sure. This is a sweet little bike! Should be a blast to ride when I get it running.

See if I can help at all.
Here is the Parts Fiche for the Ignition.




#9 should be the Ignition coil on the stator plate to power the primary side of the Main Coil for spark. As it is a magneto Ignition. No battery needed, for spark. The others are for the lights/ battery charging. The magneto coil would not go to the Rectifier, the other three would.
Ohm check the resistance back through the magneto coil, also you should see ACV here when kicking or cranking the motor. Points make and break ground. make sure the gap is right and the contacts are clean. You can set them to gap, then with an OHM meter static timing. The main Ignition coil, 6v huh, well there should be lots of those available still for a points system, even a car one should make spark for you. OHM test that one as normal, primary, then secondary.

Maybe some good reading here for you: www.strappe.com/ignition.html
www.dansmc.com/troubleshooting2.htm
www.dansmc.com/magneto1.htm

Don, I think you mean lighting coil, not lightning coil, although lightning would be cool too.

There are three magneto coils as Motorhead said, two are for lighting, and the third (looks like #9 in the photo) is called the primary. That is the charging coil for the primary side of the ignition coil. (It does not get rectified as Motorhead already explained).

Usually I see lower resistance coils for magnetos, but I guess it all depends on how the primary charging coil is wound, so 3 -ohm may work, even if it not perfectly matched.

With magnetos using higher resistance coils, you can usually go a little lower in resistance and be pretty safe, so if you have a 2.3-ohm KZ coil, you could try that as well, but more so than in the KZ-type ignition, the ignition coil needs to match the primary charging coil to get the most out of the ignition. Magnetos are not known for great spark energy, or duration, just high voltage, which a two-stroke needs (also useful high-compression race motors).

On a magneto system, you usually kill the bike by grounding the primary side of the coil. So if there is a kill switch wire in question, un-ground it to get spark, ground it to kill.

So I'm guessing I should try the #9 as the first step. Thats good cuz there are a ton of them out there and they are pretty cheap. This bike does have a battery what its used for who knows. :blink:
Here are some pics as it sits-

That a nice little bike you scored there.
With the Rotory Valved intake, it should pull nicely through the powerband. KZ250 Killer!!
Have you tested the Primary Coil #9 on the stator plate with an Ohm Meter? Or checked to see if when kicking you get ACV from it? Might be bad connections, bad points, or like Loudhvx said grounded by a bad kill switch. Check the primary #9 coil before replacing, or you might still have the same issue with a new coil installed.

Holly crap Don...
Fuel filter is as big as the cylinder.... :blink: :laugh: :laugh: :laugh:

Cool little Kawi there no doubt.... Luv it!

Old Man Rock wrote: Holly crap Don...
Fuel filter is as big as the cylinder.... :blink: :laugh: :laugh: :laugh:

Cool little Kawi there no doubt.... Luv it!

I know, that thing is huge! There is some crud in the tank so I'm thinking I should have it cleaned out before I put any gas in it. My ex brother in law is a master with a mig welder so I might even cut the bottom off and really get in there to clean it out if it looks too bad. Finding a new tank is next to impossible.

Motor Head wrote: That a nice little bike you scored there.
With the Rotory Valved intake, it should pull nicely through the powerband. KZ250 Killer!!
Have you tested the Primary Coil #9 on the stator plate with an Ohm Meter? Or checked to see if when kicking you get ACV from it? Might be bad connections, bad points, or like Loudhvx said grounded by a bad kill switch. Check the primary #9 coil before replacing, or you might still have the same issue with a new coil installed.

I have a couple days off so I'll try to get everything tested and see where I'm at. I'm hoping it's a bad ground.

I actually own the same model. Really good bike but the electrics are a nightmare. I think that I would avoid buying a new coil. I have already replaced mine (it was cracked) but the old one still sparked. I think that checking the points would be the first step. Make sure they are in sound condition and replace them if necessary. You can still buy them for cheap from a lot of sources (e.g. Dennis Kirk, Bike Bandit, eBay, etc.).

Clymer has a fairly good manual and if I get a chance, I'll try to upload it for you and others to use (have to scan it page for page). I have actually been trying to find a pdf version of the factory manual but no one has it.

One thing that you can check is the voltage to the primary circuit on the coil. It is located by the battery (above it actually). You probably already knew that.

It should read ~6 volts. If you are getting 5, recharge your battery; although, I can still start mine without the battery being charged.

Man, I keep coming back to the points. There really isn't anything that could go bad except them. Even with a cracked coil, mine still ran. You could check the coil's resistance. I am fairly certain it needs to be 4-5 ohms. NOT 3 ohms and DO NOT BUY A 3 OHM COIL...bad news.

eBay has a lot of NOS parts for the G3SS on the cheap including coils, lighting coils, etc. Just don't buy them all because you and I will have issues!!


I hope that this helps some. Like I said, just check the points, adjust/clean them. Check for any voltage getting to the primary side of the coil. You may need a buddy kicking it over while you use the test light or meter.


Good luck and share your results!!