DIY Kettering ignition upgrade?

I'm really surprised that nowhere on the Net can I find a basic schematic for a way to "transistorize" the ignition on my KZ400. There is a single set of points on my bike, they open every revolution. Seems to me I could use the mechanical advance and mechanical breaker points to trigger a transistor that would switch the coil.
Does anyone have any ideas?
What kind of transistor would you use? Would a heat sink be necessary? How about an IC, would that work? Somebody help me, my bike is running fine, and I need to break it!

Sounds like a job for Lou...Lou...ohhhhh Lou!!!! :woohoo: :woohoo: :woohoo:

you could probably use the ignition system from a cb125 early 80s and modify the timing plate to match

I'll draw one up and post it.

EDIT: I revised the circuit. The details are here:
www.geocities.com/loudgpz/GPZheiModForPoints.html


Try this. The HEI module is for many mid to late 1970's Chevy v-8 cars. It ends up cheaper than buying the transistors seperately. $15 or so.

I haven't tried this circuit, but I think it should work. If I see a problem or think of anything, i'll post here. That +12 volt source is only when the ignition is "on".



Post edited by: loudhvx, at: 2006/08/21 01:58

Yaaaay! Man, Lou, you are awesome! I am going to have some serious fun with this! I have a feeling my '76 Chevy pickup is about to be 'parked' for a while! Thanks so much, and good job with the image, what are you some kind of genius? Thanks, man!

Will that work on a 78 KZ1000?

yes but you need 2 of them

Here's one I drew some time ago without the HEI module. The main transistor and the Zener's are hard to get (They are already inside an HEI module.)

EDIT: I revised the circuit. The details are here:
www.geocities.com/loudgpz/GPZheiModForPoints.html







Note that in both designs the condenser should not be used.

I thought I had another drawing which has a switch that can be put in so that if the ignitor fails, you can throw the switch to resume normal points operation to get you home. You may want that feature since some say the HEI module is not reliable.

Also, I'll put in an LED so you can static time it using the LED as the timing indicator.

The HEI module needs to be on an aluminum plate for heat sinking. (The HEI module comes with heat-sink gel.) In this application, the module is being used very conservatively, so it shouldn't be getting very stressed out at all and should last a long time.

The Q1 transistor does not need a heat sink.

It's possible that R2 may need to be a lower value to put more current through the points.

Also, because there will be very little current and no arcing on the points, dirt will be the only worry on the points. They need to be very clean with no oil on them.

Post edited by: loudhvx, at: 2006/08/21 01:59

Thanks again Lou!

But of course there is, this design is for the kz650, but should work equally well on anything with 2 points.

www.kzrider.com/forum/4-electrical/60768...r-and-dyna-s-testing