MSefi.com read only forum (Jan.15,2018)

So a newby to MS, I've been reading about it for years, but never in a position to take the plunge.
Im running a GPZ 900 Kawasaki engine in an older D sports racer (CAR) and Im Damn tired of stepping on the gas and having to wait for the damn carbs to decide if they want to work or not (damn near killed me at a hillclimb last weekend)
So a few questions, which system would be best for an iterim setup to just run fuel delivery. I plan on using throttle bodies and injectors of a newer bike adapted to the old engine and for the short term I figured on leaving the stock CDI running the ignition, but maybe thats not the best way to go. In my experience simpler is better.
Ultimatly we want to install a Busa motor but the budget wont allow that for next season so Im stuck with the 900 which otherwise runs quite good.
I have several questions and maybe folks could point me to good threads for info, for one can I use the stock CDI tach signal(timing) to time the injectors? I would like to keep my investment to a minimum as this is an interim setup, but we could be setting some overall hill records with this car as is, if we could solve this problem and a couple other minor unrelated ones. I have read a few older posts about similar setups but want more current info. Any help pointing me in the correct directions would be appreciated. Thanks

csp54 wrote:So a newby to MS, I've been reading about it for years, but never in a position to take the plunge.
Im running a GPZ 900 Kawasaki engine in an older D sports racer (CAR) and Im Damn tired of stepping on the gas and having to wait for the damn carbs to decide if they want to work or not (damn near killed me at a hillclimb last weekend)
So a few questions, which system would be best for an iterim setup to just run fuel delivery. I plan on using throttle bodies and injectors of a newer bike adapted to the old engine and for the short term I figured on leaving the stock CDI running the ignition, but maybe thats not the best way to go. In my experience simpler is better.
Ultimatly we want to install a Busa motor but the budget wont allow that for next season so Im stuck with the 900 which otherwise runs quite good.

While any MS could work on paper, MS2 has some better features for blending a TPS and MAP sensor with independent throttle bodies, and MS3 would be overkill for fuel only.

I have several questions and maybe folks could point me to good threads for info, for one can I use the stock CDI tach signal(timing) to time the injectors? I would like to keep my investment to a minimum as this is an interim setup, but we could be setting some overall hill records with this car as is, if we could solve this problem and a couple other minor unrelated ones. I have read a few older posts about similar setups but want more current info. Any help pointing me in the correct directions would be appreciated. Thanks

Hard to say - do you have any information on the voltage or waveform of the CDI tach signal?

well i am assuming a 12 v square wave, or some semblance of one as its using standard coils and hall sensors, but its a waste spark system, so 2 coils for 4 cylinders and each coil fires once on ignition and once during ex stroke for each cyl. thats why i dont think it would work for injector timing. just not sure how would fit a degree wheel to the system, just one of many questions

Do not assume; measure.

for one can I use the stock CDI tach signal(timing) to time the injectors?

Are you sure the bike has a CDI type ignition? I ask because Kawasaki road bikes tend to have Inductance type ignitions (also called TCI) produced by Denso Corp of Japan. TCI, especially wasted spark applications of TCI, tends to be more power-hungry than CDI, but the TCI box is cheaper and simpler than CDI. For this reason, road-going multicylinder bikes with big headlights (like the GPz900) tend to be TCI, while off-road singles with no headlights tend to be CDI.

You can tell if your engine's ignition is really CDI (capacitor discharge ignition) by checking to see what the coils are hooked up to. In a CDI setup the coils will be hooked up to a ground line. In a CDI system the line from the bike's ignition box will give the coil a 250 to 400 vdc shot from the ignitor.

But if your engine's coils are hooked up to +12 volts then it's an inductance type ignition. And if you've got an Inductive ignition setup on the bike, here's a very simple circuit that works flawlessly to feed tach signal from an Indutive type wasted spark 4 cylinder motorcyle engine into the mega/micro squirt's OPTOIN+



So you'll run a line off of the coil negative lines and put the diode (IN4003) on each with the banded end toward the coil. The run 12volt power through a 1K ohm resistor and make the top branches of the "y" with these two lines. Then extend the bottom line of the "y" into the Mega/Microsquirt's OPTOIN+ line. The OPTOIN- line gets connected to ground.

If you look at this circuit you'll see why it works and why it's better than the other suggested coil-trigger methods you'll read about here in the megasquirt websites. It completely blocks out all of the coil's nasty characteristics (the noise, the "ringing", the big voltage spikes). This simple little circuit gives the Mega/Microsquirt's OPTO circuit exactly what it wants: a gentle, low voltage square wave.

I tried the other methods of coil triggering you'll find in the mega/microsquirt manual. Trying to mitigate the crazyness that goes on inside the coil is a waste of time and effort (zeners, capacitors, resistors, etc.). I had a cronic case of "resets" and bizzare tach readings during cranking. I was on the verge of trashing the whole project. I was ready to ship the bike off to a junk yard when I finally found this solution.

Many thanks to Matt_GSXR who I got it from.

It's TCI - see this thread here for a discussion of how "the CDI (sic) grounds the coil to fire the spark" (sigh) http://www.kawasakimotorcycle.org/forum ... -test.html

By the way, that's a very eloquent description of which bikes typically use CDI and which use TCI ...

By the way, that's a very eloquent description of which bikes typically use CDI and which use TCI ...

I just wander along, adding bits of other people's info to my backpack of info. That bit was a "keeper" so you have been assimilated.

I guess that in addition to crediting Matt_GSXR on that post I should also have credited DonTZ125 for the "corporate knowledge" on ignition types.

At least you carry a backpack - I have to keep wandering back over my meandering path, trying to remember under which bush I found which snippet of wisdom ...