Jump to content
Sign in to follow this  

Pointless ignition module

Recommended Posts

Hey gang, I’ve found another functional option for ditching points without inner rotor or CDI. I’ve built an ‘82 XL100S with 120 kit, ShiftUp big valve head and kitaco cam. Seems like it wants to rev and I was floating the points easily so I began looking for solid state ignition options. Because it was street legal with lights and a battery, the XL has three coils under the flywheel instead of just one like the XR. The crankshaft taper is also longer and thus would require a bottom end swap and I don’t want to source one or split cases. Poking around online I found a product from a defunct Australian company called ATOM that made transistorized ignition modules for small engines from the 70s until 2005. There are various different modules meant for chainsaws and the like, but the #9 Pink module is listed for motorcycles and trail bikes with magneto ignition. A guy in the Philippines is still selling NOS modules for $35 plus $10 for shipping which takes about 2 weeks. It took a little fiddling with the primary coil air gap but it runs with points and condenser completely removed. I even removed the spark advancer as the module has a curve built in. It seems to start easier as well. Won’t have a chance to put it through the paces for a couple weeks but I’m super stoked it’s running pointless! Hopefully I can borrow a timing light to get some numbers soon. I know there are other universal modules available for about $15 but they have fixed timing and dubious quality. 






  • Like 1

Share this post

Link to post
Share on other sites

Thought I’d share some more pics since I decided to rewire the bike to simplify and replace old wiring. I’m using 14AWG heat rated primary wire and soldering/heat shrinking all connections. Since this is a trail bike I’m not using the charging coil or a battery. Also not using neutral switch so there will now be only two wires exiting the left cover: primary spark signal and half wave headlight lead. I fished the wires through the frame and used a grommet and rtv to seal up the original case grommet. Looks pretty tidy now and I’m nerding out a little on how easy it is to run a breakerless system.










Edited by FightingRed

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this