'86 GS550 Ignition & Timing Questions

[Guest]

I picked up a basket case GS550EF, and I am looking to build my own CDI Igniter using the original pickup coils. Reading the manual I have figured out how to process the signal and what the output to the coils needs to be, but I can't seem to find a few pieces of information.

I know the ignitor controls the timing advance, but I can't seem to find the initial advance, max advance, and at what RPM max advance is achieved.

I also can't find what the output voltage of the pickup coils should be (The trigger voltage, not average). This I could determine myself though. The service manual I have indicates that a negative pulse is sent to trigger at the correct minimum advance, and a positive pulse is sent at maximum advance. As long as this is correct and there isn't a couple of degrees delay in between the trigger pulse and the spark firing then construction should be fairly simple.

My plan is to build a unit based around a cheap micro controller. The total cost would be around $20, use the original ignition system (minus ignitor), and be fully programmable for added advance. This could be a very nice DIY replacement for a part that is getting harder and harder to find.

[trippivot]

the basics just off the top of my head - may be a little off but will work excellently

11~13 original degrees

jump it to 32~36 at 1800~2000 rpms

pick up coils have 100 ~ 800 ohms and will send approx 0.3 ACV signal ..

you can get a swing needle meter and swipe a screwdriver by the pick up to test my accuracy.

GPZ 750 igniters have the advance inside .. GS1150 do too.-- pulsers are common and brains swap easy

[ryguy425425]

the basics just off the top of my head - may be a little off but will work excellently

11~13 original degrees

jump it to 32~36 at 1800~2000 rpms

pick up coils have 100 ~ 800 ohms and will send approx 0.3 ACV signal ..

you can get a swing needle meter and swipe a screwdriver by the pick up to test my accuracy.

GPZ 750 igniters have the advance inside .. GS1150 do too.-- pulsers are common and brains swap easy

Awesome! That's exactly what I was looking for! I'm waiting on a few parts to come in the mail, then I'll post what I come up with.

[ryguy425425]

GPZ 750 igniters have the advance inside .. GS1150 do too.-- pulsers are common and brains swap easy

So if I have to scrap the project and buy a new igniter, a Kawi 750 or '80+ GS1150 unit would be a direct fit? (After I splice in the wiring I'm assuming) The previous owner cracked into my ignitor, so at this point it has to go. If I can find a used one cheap that'll get the bike running while I'm construction my custom ignitor.

[JEEPRUSTY]

hmm the precise timing is in the manual
look it up on basscliff's website