This is primary information. I have not yet attempted to run the engine as I have one bum coil and I suspect the plug caps and wires need to be replaced as the spark is fairly weak but it is definitely there.
At this point, I don't know if this setup will work when the engine runs as the ignition advance curve is controlled by the igniter and will likely be somewhat off. I will report on that as soon as I can. I will also put together a tutorial in due course.
For the time being, to recap, this mod is suitable for 83 and up 550s and requires and igniter and the corresponding signal generator and rotor from an 83 and up 700 or 750. I suspect those from an 850 or 1100 may also work but have not, as yet, tried them.
The igniter box will plug right in to the harness and of course its own signal generator plug. The most difficult part of the project is fitting the pickup coil plate from the 750 to the engine case of the 550. The stock plate is 80mm in diameter whereas the 700/750s are 84mm. To get an aligned fit (i.e. where the hole in the plate correctly aligns with the end of the crankshaft) it is necessary to elongate the stock mounting holes (toward the center of the plate) and remove the locating post on the engine case that is at the 2 o'clock position (I used a die-grinder).
Now before working on the pickup plate, it is necessary to remove the pickup coils and this can be a tich difficult as the screws holding them are "locktited" in and they are slotted screws with wider than normal slots. You will likey need to fab up a screw driver to fit. It is also necessary to remove the magnets under the pickups and be warned they are brittle and break easily so I would not recommend using an impact driver to loosen up the screws.
When reassembling everything be sure to use red locktite on all screws. The rotor from the 750 will fit right to the crank with no modifications and locktite should be used on it as well.
The pickup coils from the 7 series have 2 wires coming from each and another (yellow/green) that is bolted to the lower plate locating screw. This is a ground lead. There is no connector in the harness so it will be necessary to connect it to the frame or the battery. I chose the battery.
That's about it but one further point of information. During my research, I was informed by Boyer Bransden Ignitions in England that the reason so many of the stock igniters failed is due to the fact that these models had charging systems that were prone to putting out over voltage. In this regard, I would suggest the charging system be checked immediately after the bike is running and if its found to be out of spec (over 15 volts) I'd shut it down and not run it until that is corrected.
As this project was helped by a lot of information and input from many members I would like to thank all who answered my queries, made suggestions or gave encouragement. I couldn't have done it without you. Special thanks to my buds SVSooke and Ranger who provided me the 750 and 700 series parts that made it possible. Thanks guys.
As soon as I have new coils and wires I'll get the engine running and report further.
Stay tuned.
Cheers,
Spyug
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