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Installing an Electronic Ignition

Our full kit for the upgrade includes new coils from Rick’s Motorsport in addition to the ignition kit from Elektronik Sachse. Elektronic Sachse makes ignition kits for many vintage motorcycles. Rick’s has coils to replace most vintage bike ignition coils. Photo by Keith Fellenstein

Our project this issue is upgrading the ignition system on a 1977 Suzuki GS750 from points to Elektronik Sachse solid state ignition. Once done, we won’t have to worry about points and condensers any more and can just enjoy riding. This project is relatively simple, as you don’t have to disassemble anything more than the points assembly. A good set of metric wrenches and JIS screwdrivers are all you need to complete the project, along with wire crimpers and strippers, and some zip ties. — Keith Fellenstein

Photo by Keith Fellenstein

1. Our subject bike is up on the lift. It currently still sports the original-style points ignition. Not for long!

Photo by Keith Fellenstein

2. After disconnecting the battery, we’ll start the process by removing the points cover. Three Phillips type screws hold the cover on. This is a dry assembly, there should be no oil or fluid inside it.

 

Photo by Keith Fellenstein

3. With the cover off, remove the three screws holding the points plate in the engine. These are a combo Phillips/flat blade screw, but the Philips part was burred out beyond use, so I used a flat blade to remove them.

Photo by Keith Fellenstein

4. You may need a shot of penetrating oil to help with removing the nut holding the points cam in place.

Photo by Keith Fellenstein

5. A 12mm socket and wrench will remove the bolt holding the points cam in place.

Photo by Keith Fellenstein

6. Once the bolt is out you can remove the points plate and the timing plate behind it. You won’t use either of these anymore, so put them somewhere you can find them if you should for some reason want to convert back some day.

Photo by Keith Fellenstein

7. The points cam just lifts out. Store it with the other spare parts.

Photo by Keith Fellenstein

8. Now it’s time to remove the gas tank. It’s best to have an empty tank, but if you can’t empty it, make sure the petcock is not set to Prime. Disconnect the fuel hose from the tank and with a wrench and 12mm socket, remove the bolt at the back of the tank.

Photo by Keith Fellenstein

9. Wiggling the tank while pulling back on it will ease it off the rubber buffers at the front. Then you can lift it off and set it aside in a safe place.

Photo by Keith Fellenstein

10. The old coils still worked, but since we’re upgrading the ignition, we may as well upgrade the coils too.

Photo by Keith Fellenstein

11. We’re reusing the plug caps, so unscrew them and put them aside for now.

Photo by Keith Fellenstein

12. These resistor caps can get corroded and increase their resistance over time, so it’s a good idea to take them apart and clean them. Usually there’s a slot in the part that captures the thread at the top of the spark plug. Use a screwdriver to disassemble them as shown here.

Photo by Keith Fellenstein

13. It’s a good idea to make note of the cylinders the coils fire as a reminder for reassembly. Also note if the plug caps have different configurations for the inner cylinders.

Photo by Keith Fellenstein

14. Use a 10mm wrench to loosen the nuts holding the coils in place.

Photo by Keith Fellenstein

15. Notice the unused (for now) mounting holes on the frame bracket.

Photo by Keith Fellenstein

16. The new coils are shorter in length than the old coils, so we’ll make use of those other mounting holes.

Photo by Keith Fellenstein

17. Move the mounting bolts and stand offs from the old coils to the new coils.

Photo by Keith Fellenstein

18. Now the coils fit perfectly in the unused holes in the mounting bracket.

Photo by Keith Fellenstein

19. I could have just modified the wiring harness to fit the spade terminals on the new coils, but I hesitate to change the harness. I wouldn’t want to be called the DPO (Dreaded Prior Owner) when the next owner changes them again.

Photo by Keith Fellenstein

20. I didn’t have any wire that matched the original harness colors, so I made more notes to keep the circuits organized.

Photo by Keith Fellenstein

21. With the harness adapters wired in to the coils, it’s now time to mount them permanently.

 

Photo by Keith Fellenstein

22. After cleaning the resistor plug caps and trimming the high voltage wires, the plug caps are screwed back on. Getting a good connection here is key, and it will take some effort to get them started. Don’t forget to put the rubber end caps on the wires first.

Photo by Keith Fellenstein

23. The new pickup plate is a little oversized for the mounting location, so there will be some fitting required here.

Photo by Keith Fellenstein

24. I started off with emery cloth and a file, but soon moved on to a Dremel with a sanding drum to speed things up.

 

Photo by Keith Fellenstein

25. Now the sensor plate fits snugly enough, but can still be rotated for timing the ignition.

Photo by Keith Fellenstein

26. Place the new rotor stub on the end of the crankshaft, aligning the notch in the stub with the pin in the crank.

Photo by Keith Fellenstein

27. Center the pickup plate screws in the middle of the slots on the plate so you have room to fine tune the timing.

Photo by Keith Fellenstein

28. Slip the magnetic rotor over the rotor stub. Leave it loose for now.

Photo by Keith Fellenstein

29. Tighten the bolt that holds the stub to the crankshaft end. It’s a small bolt, so don’t overtighten it.

Photo by Keith Fellenstein

30. Find a suitable place to mount the black box ignition controller. We’re using some space behind the left side cover.

Photo by Keith Fellenstein

31. Trace the leads from the old points plate back to where they connect to the wiring harness and disconnect them.

Photo by Keith Fellenstein

32. Fish out the old leads that connect to the points plate and remove the old assembly.

Photo by Keith Fellenstein

33. The kit came with a round weatherproofing grommet for the points cover but we wanted to use the old fitted grommet, so we carefully slid it off the old harness.

Photo by Keith Fellenstein

34. It slid right on the new wiring for a neat appearance.

Photo by Keith Fellenstein

35. Here is the grommet fitted to the case with a nice, neat wiring arrangement.

Photo by Keith Fellenstein

36. Run the new ignition harness back through the places where the original harness ran, to the new ignition controller location.

Photo by Keith Fellenstein

37. Here they are, ready to connect to the new controller.

Photo by Keith Fellenstein

38. Connect the wires to the appropriate terminals on the new controller.

Photo by Keith Fellenstein

39. We had to make a couple of short jumpers to connect the controller to the main harness to the coils.

Photo by Keith Fellenstein

40. Finding a source of switched 12-volt power was easy, but getting a focused picture was not.

Photo by Keith Fellenstein

41. We crimped a lead to the switched 12v source and prepared to heat shrink some insulation over it.

Photo by Keith Fellenstein

42. After applying a little heat from a heat gun, we now have an insulated power connection.

Photo by Keith Fellenstein

43. Now it’s time to set the timing. Rotate the engine until the outer cylinders are at TDC. Turn on the ignition. Rotate the magnetic trigger until the LEDs just go out and lock the plate with the set screws.

Photo by Keith Fellenstein

44. Using the supplied Velcro tape, attach the controller to the space chosen for it. Replace all the parts you removed for access and enjoy your new maintenance free ignition system.

Published on Feb 3, 2021

Motorcycle Classics Magazine

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