Digital Electronic Ignition

[WMarshy]

I happened to come across this digital electronic ignition system on ebay for the XS and was curious if anyone else was familiar with it. Are there any other options out there for the DIY'ers? I vaguely recall someone using some GM sensors to make their own ignition system but believe it was complementing their fuel injection/Megasquirt. Anyone recall a stand alone digital ignitiin setup?

Sachse Digital Electronic Ignition ZDG3 Yamaha XS1100

http://pages.ebay.com/motors/link/?n...d=271175624971

[crazy steve]

One big disadvantage to this type is ignition is the loss of the vacuum advance, and the corresponding loss of fuel economy. You can somewhat compensate for this with the curve selected, but it will be a performance/mileage tradeoff usually, with one or the other suffering.

About the only advantage is these aftermarket ignitions can usually drive a higher-output coil compared the OEM box, so if you're going racing and/or running nitrous or a turbo, these give you more ignition options.

My Harley uses a similar ignition, but the big difference is there's 'switchable' curves that are changed via a VOES ((vacuum operated electric switch) that emulates a vacuum advance. Disconnect the VOES, and you'll drop 5-7 mpg in 'normal' riding. This is very similar to the XJ ignition...

[FJ111200]

At $400 for that box and pick ups alone, you could buy an XJ1100 box, pick ups and carbs for the XS and still have some money left in you pocket, and get a return of 48mpg, with no loss of power and a smoother engine. I am, on both my XS's.

[jwhughes3]

Are you saying you swapped in a complete XJ ignition and carb set to an XS?

I would not have thought that would work - guess they are not that different.

John

[FJ111200]

Yep, on both my XS1100's.
The only thing i didn't use was the boost unit from the XJ.
I couldn't wire it in, but found that it wasn't needed anyway.
TomB told me how to wire it but it was lost on me.
Anyway, best thing i've ever done to my XS's apart from ride them. Oh, and all the other mods.

[WMarshy]

Yep, on both my XS1100's.
The only thing i didn't use was the boost unit from the XJ.
I couldn't wire it in, but found that it wasn't needed anyway.
TomB told me how to wire it but it was lost on me.
Anyway, best thing i've ever done to my XS's apart from ride them. Oh, and all the other mods.

Care to explain more about the ignition conversion? Sounds like a good upgrade to me... maybe not the carb swap, I'd like to go with the ZRX carbs in the future.

[FJ111200]

It's basically plug and play.
The pick up coils bolt straight on but i think i swapped the XJ connector over to fit on to the XS. The other connector from the XS is a straight plug in.
I tried running with the XS carbs at first but it was a bit crappy and as soon as i fitted the XJ carbs the difference was obvious. I left them with standard XJ jetting. I blanked off the boost unit spigot, as a said i'm not using it.
I don't know about using the ZRX carbs, you'll probably have to experiment there, but for me the XJ's are the ones to go with, without piddling about.
Yeah i was that impressed with the set up i did it to my other XS.
Both bikes rev smoothly right up to 100mph no problem, not been any faster, not bothered about it.

[crazy steve]

Care to explain more about the ignition conversion? Sounds like a good upgrade to me... maybe not the carb swap, I'd like to go with the ZRX carbs in the future.

The XJ ignition will bolt-on to a XS, but you'll have to move some pins in the plugs to the TCI; careful comparison of the two wiring diagrams will show you what's needed.

Is it an upgrade? Well, not really IMO. If your stock XS ignition is going bad mechanically (mechanical advance is worn, advance plate isn't moving freely, bad vacuum can), then the XJ unit will cure all those ills as it has no wearing mechanical parts. There's a little difference in the advance curves, but the XJ is slanted more toward mileage rather than performance, so depending on what year the XS is you may see a power loss. You'll now have harder-to-find parts too. Not hooking up the 'boost unit' means he's left a few mpg on the table and you won't get any extra advance at partial throttle openings. His '48 mpg' is imperial gallons, that's about 38 US.

[FJ111200]

The XJ ignition will bolt-on to a XS, but you'll have to move some pins in the plugs to the TCI; careful comparison of the two wiring diagrams will show you what's needed.

Is it an upgrade? Well, not really IMO.

Yeah, now you remind me, but all that's needed is to swap over the orange/pink wires at the ht coils.

We started having a bit of a debate on the UK forum about it being an upgrade. Each to their own. I prefer it.

[crazy steve]

Yeah, now you remind me, but all that's needed is to swap over the orange/pink wires at the ht coils..

If you connect the 'boost unit' ('vacuum' advance), you need to shuffle a few more wires and re-task them.

The XJ ignition is a 'upgrade' from the standpoint as there's no wearing parts and the curve will likely improve mileage slightly (if using the XJ carbs), but also limits you to fixed static timing (no adjustment) so if doing other mods may give you issues.

Different strokes for different folks....

[crazy steve]

Ideally, if someone offered an aftermarket ignition with a knock sensor input, that would be the hot ticket. But the difficulty of retrofitting the sensor to the XS motor (or any motor not originally equipped) to get an accurate signal is the back-breaker....

[FJ111200]

If you connect the 'boost unit' ('vacuum' advance), you need to shuffle a few more wires and re-task them.

Different strokes for different folks....

Yeah, and looking at the wiring diagram that was the hard part and gave me a headache. As i said, it's not needed anyway.

Yep, deffo.

[clcorbin]

Ideally, if someone offered an aftermarket ignition with a knock sensor input, that would be the hot ticket. But the difficulty of retrofitting the sensor to the XS motor (or any motor not originally equipped) to get an accurate signal is the back-breaker....

Retrofitting the sensor is trivial compared to programming the digital signal processor to properly filter all the noise THESE engines make out and actually hear only the true knock sensor. THAT is hard as hell. I'm will to go out on a limb here and say the XS11 has NEVER been characterized for knock!

What WOULD be possible would be to retrofit the ignition system with a coil on plug system that did not use any vacuum or mechanical advance and was still vacuum referenced. I'm (SLOWLY) working on that for my bike. Long term, it will be part of a custom PCM system (not megasquirt), but I want to start by leaving the carbs and replacing the ignition system. I have machined a 32-1 tooth wheel that replaces the mechanical/vacuum advance mechanism and bolts directly to the crank like the stock system:


Other view:


The system I have planned/partially built will use LS2 coils (1 per cylinder) as they have built in ignitors and dwell control along with a HOT spark (factory and aftermarket XS coils are a joke in comparison). It will use the 36-1 wheel along with a Yamaha R1 crank sensor for timing control, a pressure reference to the existing vacuum port on the #2 carb and a Vr sensor mounted on the back of the valve cover to get a cam sync pulse from one of the cam lobs. The controller is based on the Open5xxxECU code (ignition only at first) but will be completely custom hardware as those guys want WAY more hardware than I need for this bike.

Unfortunately, I planned on having this done a year ago. Life kept getting in the way.