I have a feeling that starting on a custom build CDI may provide a good start for such an undertaking, as it would already have to deal with most of the important stuff like RPM sensing, TPS reading and other things. Definitely an interesting idea! Please do tell us about what you're working on, if possible.

All I will tell you is to go take a look at some far larger projects in the open source community and then tell me that again. It has already been proven that even big projects can make progress even with all members sitting on opposite sides of the globe provided there's some good people coordinating the whole effort.

Now that's something! Yet another person who's working on something like this, I never thought there would be more people working on such a thing. (I had a feeling that Joel would be working on it, he'd dropped enough hints.) And please do keep us updated if you can. I'm definitely interested, even if there's no such thing as getting a project off the ground, having a place where people can get information about these systems is a good thing.

^^ Will keep you updated once the CDI starts working! Maybe, I will have something concrete to share in around 15 days.

am currently planningto plonk the p220 setup on the classic engine [budjet constraints] my idea is still on paper work will begin in another week. altough for my project i do not need the waste spark system dat the pulsars use rather in need simultaneous firng if someone cud help me out with that

I have not gone through the whole thing here yet did not have time. but My mechanic or say tunner has recently taken the FI from a yamaha 150 cc bike i dont know what exact bike it was. and plonked it to his CRUX. his crux also has 5 gear. though i know its not the best bike to keep experimenting with. but the bike is rev happy, good eficiency and also decent power as for a comutter

Whoa!

Must be the R15's unit! How is it working? Plz, need more details....

I would honestly be really surprised if such a conversion could be made. The R15 is a high revving 4 valve liquid cooled engine. The crux is a 100cc two valve air cooled engine. I can't image it would even start, since the ECU would make the crux engine run so rich it would drown in fuel. That is unless he would have been able to remap the entire fuel map etc, which we all know isn't possible with the R15 ECU. (Maybe possible if you're having yamaha's equipment.)

Why do you want to change from the waste spark ignition system? Any specific disadvantages that you want to eliminate?

So would I! Thats why I asked for more details. Which other 150cc Yamaha bike has Fi?

well the waste spark systems energise the sparks every time the piston reaches TDC be it the compression stroke or be it the exhaust stroke,so to eliminate pre ignition problems that will pertain for this specific fuel also due to running of avery lean a/f ratio a simultaneous firing system becomes mandatory.

also could someone help me with as to how could i alter an engine's compression ratio, i mean some real heavy changes in compression ratio's will require what changes in the internals?

There's the R125. But I doubt he would have gotten his hands on the (probably) closed loop FI system it uses. And again same issues remain, completely different engines. I somehow doubt he has actually converted his crux to FI. If true, I'd love to see some pics of the setup. Till that time I think I'll regard this one as an urban myth, considering the difficulty involved with doing such a conversion. However, it is possible the guy took the CDI unit from a 150cc bike, that might work.

To get rid of the wasted spark system you probably need to get your sensor signal from a different location. If it currently senses the position from the flywheel, you're never going to be able to find out if it's the TDC of the compression stroke or the exhaust stroke. I believe you'll need to sense it on the camshaft. Perhaps in combination with the flywheel sensor.

And to radically change the compression ratio, you'll probably have to go for a different crankshaft. Or maybe a shorter connecting rod, since that can also affect the space left above the piston at TDC. (Now, I'm not a mechanic, but basic physics says these two things affect compression ratio.) For small changes in compression ratio you could perhaps do the opposite of shaving the head. Add a spacer between the crankshaft housing and cylinder. Of course, that could be more trouble than what it's worth, getting it to be leakfree could be an issue.

@All:
Those that are working on any projects like custom CDI modules or even FI systems. If you're in the position to post a description, it would be greatly appreciated.

FYI, ppl the R125 and R15 uses the same ECU/pump/injector/manifold etc and the fuel metering is the same.

Now shoving an FI system from another bike and calling it as a development is stupid coz thats not R&D. You develop your own system and taking it to next levels makes sense. In India everybody looks for shortcuts. Hack somebody else's tech and get better. Nobody wants to dirty their hands and brains.
Like most of you have discussed, if developing an ECU was that easy, we would have some really interesting machinges around. There are a lot of people striving hard to make their own ECUs in this country and the moment they realise what it takes to build one, they back-off. Its not impossible, but its a task on its own. A very big task.
Developing a CDI is far more realistic. Gives you more learning.
A more simple approach to build an ECU is by hacking some megasquirt ECU and making it work to your needs. So your base development efforts are saved.
In the end, you really need to make the mechanicals co-ordinate well with the electricals else its a disaster.
I'm already working on an FI project and I am collecting data. Its being tested and the performance gains are very inspiring. I need more track-time, dyno time and engine data to refine the package. Working on making an carb engine to FI is already done and I'm only waiting for some time to deploy the system on my carb engine.
Transplanting some other bikes system is not called tuning, thats fitting.

Again so true. But I sense a certain frustration from this post as well.

@all:
I want to emphasize again, I intended this as a discussion thread. Building something as complex as an FI system is out of scope for this thread, but we can share views and insights here. Also, I'm asking people to post descriptions of their projects, if possible. But withhold as much information as you think is needed. I'm not in the copying business, and I definitely don't want to encourage any persons who want to make a quick buck by stealing some one else's hard work.

AFAIK, a waste spark ignition system only limits the max RPM capable by the ignition system to half of the theoretical value. To eliminate it, you need to sense it in the spark plugs. What is done is that a low voltage of about 100V is sent across the spark plug. The resistance across the plug is used to find out the state of the engine. At compression stroke, resistance is lower compared to exhaust stroke.

To increase CR, you also need to design effective squish bands in the cylinder head, else detonation becomes a problem.

Hey JOEL with all dues respect and no offence been taken by me and not being offensive, i did not call it to be a development just go through my post for the same. it was just picking up the correct suiteable stuff and fit it into the Bike and get it to work fine. see Iqbal is the name of this guy. he may not be into technical numbers and all that but he can give a rough idea of what can be done. any ways. yes this was no develop ment. talked to him he said that he is not sure of what bike was it from but he mentioned that there were some bikes in india brought before launching the Enticer and they were 150 cc single cylinder, crusier styling and had Fi with front and rear disks.

Lets throw this discussion in a different direction? Who has any idea what is needed to run a CDI? I'm not asking you to post schematics. Which bits of information would be required to determine ignition timing?

I expect something like:
1) RPM
2) Throttle position
3) Temperature?
4) Crank angle (TDC signal?)