@ joseph: can you please help me about location from where to take this pulse input. I enquired from one mechanic and as per him input should be taken from sniffing into spark plug wire. I am bit sceptical about this mechanic advice as you said spark voltage is in range of tens of thousands. My idea is ...to take it from location from where you are taking to measure RPM. If possible, a pic would be of great help. second , for powering this meter can i run direct wire from battery ? Thanks !!!

Bro,where are you?Seems as if you are out on a Sunday trip.I'm waiting for the pics.Please make it fast.I'm feeling really isolated.

Where on earth did you get that from :-o

To find the wire I took, open the Left side panel, there will be a rubber sleeve with some connectors. Raise the sleeve to the top so you can see the connecters. Among the wires, one will be an isolated green+yellow wire with a seperate connector and not housed into the molex connecter. along with the other wires. That is the wire I took. But first we need to find out what inout works for your meter. If you dont want to test on your bike, another way would be to get a 240v to 9v or 12v transformer and connect 230v to ac and one wire of output to meter pulse input and other to ground. Power the meter from another 12v source. If it doesnt work like that or from the wire I said, then it should be designed for the spark plug voltage. For the power, you can connect to the ignition key, so it doesnt run when switched off.

Actually I am ecstatic. Tachometer is only thing that I wished to have in my bike which was missing in Twister and I GOT it . Actually there are quite few chinese vendors who are making these kind of tachometers. As I know Delhi is hub for all chinese imports, I searched in Karol Bagh and got it. But I really liked your bike's tachometer, its quite good job. Problem with my tacho is ...it needs to fitted outside . But still something is better than nothing.



Bro, as always I am really thankful to you for this information.I looked for any piece of document/technical specs within box but sadly nothing was found. So I am gonna rely on your advice. First, I will connect to point from where you are taking input. It will safer that spark plug input and even if it does not work it will not atleast harm meter itself because as you said it is just 10v ac. This is my thought, what you think ? For ground wire, I think I can use bike chasis. For powering the meter.....should we use 9v or 12v source ?

Bro,you didn't upload the tyre change pic.Please do.

So the below pic shows my present instrument console. The whole console is ambient lighted by a white led strip. Stock 5W lamps were removed, and this strip wired to ignition key so this pic represents with ignition key on and engine off. No glowing of meter console with rpm. Earlier it was blue, but the red parts of the dial and odometer were unreadable, so switched to white and all my friends loved it. The Digital tachometer can be seen next to it, it displays 'OFF' when engine is not running and the rpm in Thousands in 2 digits with one decimal point. The 'OFF' indicator was an idea of mine to avoid showing 0.0 and took just 2 lines of code
le, but the problem is they have to be installed outside. I dont know how they work, but this project of mine works on a simple idea. There is a firing signal line from the flywheel to the CDI ignition unit which fires the spark plug. The line is connected to a tiny coil inside the gearbox and a magnet is stuck on the flywheel which when passes by the coil on every engine rotation generating a voltage near 10v ac and tells the cdi to fire the sparks. This technology is from Honda and every bike has it built in. So after some research, I came to find that there is a pulse for every rotation meaning it indicates the engine RPM. I designed a frequency counter using the chip and Hitech C to count these pulses per second. After some interesting maths inside the chip, it displays the engine RPM live on the display. The spark plug line has over 20,000V and it is very hard to use it for precision electronics, so while tinkering I found this line, which helped me build the project. There is no cutting involved, just insert the wire to the existing connector from the engine and power the circuit from the ignition key and you are good to go. I dont have a real tachometer to calibrate is precisely, but as far as my calculations are correct, the error should be +/- 200RPM which is negligible. My driving is based on the tacho, I rarely check the speedo. I drive with the tacho and I get excellent mileage.

Looks better than the tiny stock one.Thanks bro.I too am planning of a tyre change.

Nice work bro. My speedo meter is also looks same but i'm using T10 LED's instead of LED strip. Digital RPM meter is really good. If possible detail it in separate thread, will be usefull for every one.

I'll show you another angle later.. It looks better than this pic in real. As wide as a 150cc's tyre and makes the bike look normal rather than tiny. Cornering is good, mileage and ride height increased owing to more diameter for this tyre, and braking improved several times, still not what I expect out of a tyre, but thats the best we can get with the hard compound.