Magnetos don't need a battery to generate an ignition spark. They're popular on the Pans and Shovels because then you can run the bike with no electrical system. It's for the real die-hard kickstart guys.

 

Why didn't he use drum brakes too?

 

Magnetos use points and points vary timing a rediculous amount +- 9 degrees !!! Any electronic ignition is MUCH better than a magneto or any point system for that matter. It is true that a mag doesn't need an electrically system but that isn't a reason to run it and it isn't just for die hard kickstart bikes either.

Mags are beefy looking and do allow you to start the bike no matter what the condition of the electrical system is, burnt, dead battery or no electrical system at all ... it will still start. Now if you have EFI, forget about the Mag.

With all that said, I run a Mag (Morris M5) and love it but it really offers no performance gain. I also have a full electrical system, battery and electric start. I have started and rode my bike home with a completely dead battery, has a kicker too.

Joe Hunt is a Magneto manufacture as is Morris.

 

Its true the Mag needs no battery for the spark but there are more advantages to a mag than that. The Mag is an AC current ignition which will saturate the coil MUCH faster than the old point systems could, faster saturation time allowed for higher rpm running with less spark misses. One disadvantage of the mag is they normally run in the full advanced position which made rough idle and rough low rpm performance. Todays electronic ignitions saturate the coil much faster than the Mag and with a advance from 15* BTDC to 50 * BTDC for a wide power band. I should mention that the Mags today do have a advance system in them but not as good as the electronics we have today, the Mag advances 35* if memory serves me correctly. The Mag runs a .015 point gap and a .018 plug gap, todays ignitions run a .042 plug gap which gives a longer duration spark for a more complete burn. Give me the Battery and lights over the Mag with no battery any day.

 

The Morris M5 Mag doesn't run an advance system like Doc pointed out but instead it runs a Retard system. Most ignition are adjusted for retarded conditions at start and then as the RPM increases it advances the ignition, thats called the advance curve. The Morris M5 on the other hand gets set for full advance and then if the RPM is below a certain amount it then retards the ignition to compensate for the RPM's, like when starting the bike. It is called and automatic retard system.

 

Thanks....

Thanks for the responses. I always thought they looked cool, but never saw one in use on a TC til I saw the custom bike in the American Iron article.