Can someone explain how that ignition system works on a 79?

[mklang]

I was checking my spark today and it seemed weak. I am unfamiliar with these ignition systems and was hoping that someone with some free time could give me a brief synopsis of the ignition system components and what they do.

THANKS!

[doctorgonzo]

Someone will chime in who can explain better than me, but a 79 has "points". It's a "mechanical" ignition. Two contact points under the right side front side cover alternately connect or break a circuit, that I believe provides a ground to an ignition coil. This causes the charge in the coil to discharge, firing the plugs. Search for the "coil Relay Mod", it will likely solve a huge part of your problem, though points, coils, wires, boots, plugs, could all be playing a part as well.

[Big T]

Someone will chime in who can explain better than me, but a 79 has "points". It's a "mechanical" ignition. Two contact points under the right side front side cover alternately connect or break a circuit, that I believe provides a ground to an ignition coil. This causes the charge in the coil to discharge, firing the plugs. Search for the "coil Relay Mod", it will likely solve a huge part of your problem, though points, coils, wires, boots, plugs, could all be playing a part as well.

That's pretty much it, except you forgot the condensers!

Weak spark can be any number of things. Start at the points. If you don't know when they were last replaced, new points and condensers are the place to start, along with checking to see if you've got 12V at the points and the coils

Many people (me included) upgrade to a Dyna electronic ignition (about $125) so you never need to mess with points again

BTW, when you say weak spark, what color is it?

[BassCliff]

http://members.dslextreme.com/users/bikecliff

Hi Mr. klang,

There's a service manual on my site which may help you. Sorry the pics are low resolution, but the price is right.


Thank you for your indulgence,

BassCliff

[TheCafeKid]

Frankly, switching to a Dyna system from P&C type ignition is one of the best mods you can do on one of these older bikes. Its almost essential. The old system works well enough, but it can be a PITA to maintain and mess with. The Dyna system is a set and forget set up. Once you get it timed the first time, you'll likely never have to mess with it again. Its a bit expensive, yes, but if youve got in your plans to do any type of motor mods, you'll find that to get the most out of your ignition, the big fat hot spark you need, the points and condensor set up simply will not handle it. The coil relay mod is a good addition as well. If you DO decide to swap to Dyna, I would recommend using their coils as well. Its another 120 or so for the coils, but they are designed to gain maximum output from the Dyna system, and it makes changing out your plug wires cake, as it uses wires with caps on both ends, like a car.

[mklang]

how does the dyna system work without points?

[doctorgonzo]

how does the dyna system work without points?

It's an "electronic" ignition, just like any car or bike made after about 1980 has.

[78_jee_ess]

So for a 1978 GS1000, which dyna system/coils are right?

[doctorgonzo]

So for a 1978 GS1000, which dyna system/coils are right?

Dyna S is probably the best bet.