How to prevent ignition problems

[Deleted member 12676]

My spark (at the plug) was going weak and only sparking when I spun the tire fast. (The bike died on me while riding today). Using a cheap analog Radio Shack voltmeter on the 50v AC position I could see the coil putting out 20-35 volts, depending on how fast I spun the tire. That seemed a little low from my experience with motorcycle ignitions. Measuring the coil (black to blue wires) I was in the right range (close to 330 ohms). Finally I noticed that the coil had a poor ground connection to the engine because the metal plates (that run thru the coil) were varnished, including where the screw heads touched them, which keeps the ground from the coil, which solders to the plates, from connecting good electrically to the cases.
So I ground down the plate where the black wire connects to it so that there was bare metal. I also soldered the black wire to the eyelet because it was just crimped to it which can get a poor connection over time.
So I heartily recommend doing these two things to your ignition system to keep things working right.

 

[ibdennyak]

My spark (at the plug) was going weak and only sparking when I spun the tire fast. (The bike died on me while riding today). Using a cheap analog Radio Shack voltmeter on the 50v AC position I could see the coil putting out 20-35 volts, depending on how fast I spun the tire. That seemed a little low from my experience with motorcycle ignitions. Measuring the coil (black to blue wires) I was in the right range (close to 330 ohms). Finally I noticed that the coil had a poor ground connection to the engine because the metal plates (that run thru the coil) were varnished, including where the screw heads touched them, which keeps the ground from the coil, which solders to the plates, from connecting good electrically to the cases.
So I ground down the plate where the black wire connects to it so that there was bare metal. I also soldered the black wire to the eyelet because it was just crimped to it which can get a poor connection over time.
So I heartily recommend doing these two things to your ignition system to keep things working right.

I have to agree with you 120% I haven't run a HT in a couple years, but when I did, the ignition system was always a problem. I live in a rainforest climate. Probably rains 320 days a year. My bikes would run fine until I rode in a heavy rain. Next time I tried to start them, they wouldn't. No spark. Take everything apart and put it back together and sometimes they would run and sometimes not. Put in a new CD and mag and they would run again.....until the next rain. Probably just a matter of cleaning up the metal so that at least it would rust indicating a bad connection would have done it.

The odd part always was that normally the components would check out on a vom. Soldering the little eyelet on the ground is also a good idea. i've had a few of them burn or break off.

 

[Deleted member 12676]

Yeah, I think this tip will greatly reduce the sales of magneto coils. With so much varnish on there I don't see how it ever worked in the first place.

 

[RdKryton]

This is good info!
Good post.

Jim

 

[DuctTapedGoat]

I've done it with a wire toothbrush and I've done it with a cutoff wheel. Best most solid grounding location I've found is right there at the CDI. Get the paint off from under the bracket and just screw it on. The water bottle screw just isn't solid enough, even after it's cleaned up.

Of course now, be sure to clean that contacted area seasonally, it will oxidize! There's even another thing in line with that, but I can't remember. >_< I will post here when I remember, no later than my next build.

 

[Goat Herder]

Seal the magneto cover this prevents rain and future oxidation or shorting out from any part of the magneto windings.. I use dielectric grease on my ground connection. Or I simply screw it tight and cover it with silicone and always put a dab at the grommet for any rain.. I always solder all my connections.

 

[Goat Herder]

Also with the cdi spark plug wire I eventually change mine to something more better. I put dielectric grease at the cdi connection as well where the cork crew is..

 

[Dave C]

Big problem is where the wires run out of the case there's no seal. That little nylon compression seal is nearly worthless at stopping water from entering the magneto. Especially with the front tire spraying right into it.

Take the cover off and loosen up the fitting, take it apart. Get your tube of silicone and fill the inside of the parts and reassemble, use lots of silicone inside and outside of the fitting.

It's another problem with the gasket sealing surface. The bolts are not sealed. They are open to the magneto compartment. A shot of silicone under the boltheads will seal the bolts off and still be removable if needed.

This should help some of the bad weather riders.

 

[TucsonDIrect]

+1 my best advice is to use the Battery protection spray they sell at auto parts store oryour local bigbox. Leaves a nice red coat of divine intervention