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Discussion Starter · #1 ·
Okay, so this is kinda long, but I am very stuck, and wanted to give as much detail as possible. I have been building a first gen bandit for a while now. Just finished rebuilding the motor, and while it was apart I had the transmission countershaft drilled and tapped to accommodate the 2nd gen bandit speedometer rotor/pickup. The whole idea was to eliminate the stupid magnet on the front wheel sensor that I had to use after I swapped out for the Busa forks, by hooking my Acewell 2803 up directly to the stock 2nd gen speedometer sensor that reads off the front sprocket.
Everything is back together now, and I have a 2nd gen sprocket cover with the sensor on, but I am having a hard time hooking up the Acewell to the sensor. Has anyone ever attempted this before? Is it even possible?
I found that the two wires coming from the Acewell uni-sensor are positive + and negative - and that when the magnet passes the sensor it cuts out the positive wire, causing a pulse to the speedometer that starts the whole process. For the stock sensor I haven't been able to test a working one, so I am kinda just guessing. There are three wires coming out of the sensor, one black/white which is ground, and two others (back/red, and black) which I am assuming are positive and negative. The schematic shows the two wires running up to the speedometer, with a 12v power being the only other wire going into the speedometer. I took a guess and connected the positive wire from the Acewell to the back/red wire from the sensor, connected the negative wire from the Acewell to the black wire from the sensor, and ran a seperate ground to the third wire. This didn't work. I tried a few more ideas with no luck and I am really stuck. I looked up the sensor and found that they are pretty much the same on busa's and certain years for the GSXR and Katana's. If you have any input that might help me figure this out, or could take some readings from your working stock sensor I would very much appreciate it. I really do not want to go back to that uni-sensor, haha.
 

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Magnet sensor speedo's work by magnetic flux. The sensor is a tiny coil. When the magnet passes by it, it generates a very small amount of electricity that the speedo picks up. It counts the frequency of these pulses, and with the outer circumference, calculates speed. Your stator is the same thing hugely scaled up. The sensor itself does not need supplied power to work, and if you are doing this is why it isn't working. The two wires from the sensor supply the tiny pulse of power for the speedo to read.

If you are using an aftermarket speedo to the stock sensor, the pulses may not be the same strength/duration as your acewell is expecting to "see".
 

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Discussion Starter · #3 ·
Magnet sensor speedo's work by magnetic flux. The sensor is a tiny coil. When the magnet passes by it, it generates a very small amount of electricity that the speedo picks up. It counts the frequency of these pulses, and with the outer circumference, calculates speed. Your stator is the same thing hugely scaled up. The sensor itself does not need supplied power to work, and if you are doing this is why it isn't working. The two wires from the sensor supply the tiny pulse of power for the speedo to read.

If you are using an aftermarket speedo to the stock sensor, the pulses may not be the same strength/duration as your acewell is expecting to "see".
Good to know. is there any way to test this and/or modify it if I find different readings between the two? I almost got the chance to poke around a gsxr with the same sensor at work, but didn't have enough time to throw a meter on it unfortunately.
 

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Is it not working at all, or reading something crazy?
 

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Discussion Starter · #5 ·
Is it not working at all, or reading something crazy?
not working at all, which is what puzzles me. I connected everything up, and put it in first gear on the center stand, even revved it a bit to get the wheel moving, but go no readings at all. If it was working and just reading erratically I could just recalibrate the thing.
I pulled a shop manual for a first gen busa today and copied down how to test the sensor (same sensor between 2nd gen bandit and busa.) I am going to test it out tomorrow and see exactly what kind of readings I am getting from either end, but the sensor should be getting 12v as I figured. I am going to run some more tests tomorrow and see If I can come up with anything.
 

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Discussion Starter · #6 ·
So I put a volt meter on the speedometer wires, and its reading around 6v coming from the speedo. The sensor test diagram makes it look like there are 12v supposed to be going to the stock sensor I am trying to get plugged in. Does that mean there is not enough voltage going to the stock sensor to power it? Is there any way to change that? Here are some snap shots of the diagrams I am working with.



 

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Discussion Starter · #8 ·
I'm not entirely sure. I did notice one major difference between the two switches. On the acewell switch there is just a circuit that is completed by a magnet on the wheel. You can take the two wires and tough them together to get readings. With the suzuki sensor the magnet is built in, and it reads as something magnetic passes by it. Maybe that is the reason for the difference in voltage? I really wish I knew more about electronics.
 

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I'm not entirely sure. I did notice one major difference between the two switches. On the acewell switch there is just a circuit that is completed by a magnet on the wheel. You can take the two wires and tough them together to get readings. With the suzuki sensor the magnet is built in, and it reads as something magnetic passes by it. Maybe that is the reason for the difference in voltage? I really wish I knew more about electronics.
so they are opposite? most aftermarket gauges use a sensor to read a magnet as it passes by, and most manufacturers sensors (im using crank sensors in cars as an example, suzuki may be similar) use a powered magnet to read "teeth" or pieces of metal to give a repetitive reading as whatever it is spins.

i think youre onto something.
 

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Discussion Starter · #10 ·
Yeah, think that might be where the problem lies, BUT, I really have no idea where to go from here. In the end the Zuki sensor should be making a pulse just like the Acewell sensor would, though they use different methods to make the pulse. I am not sure if maybe I could boost the voltage enough to power the sensor, maybe it would work? Maybe if I tried running 12v directly to the sensor and then sent the negative back to the speedo? I'm not too sure if that wouldn't blow something up, haha. This is getting a little out of my league.
 

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if you take a piece of steel and move it across the sensor, does it show up on your multimeter? stocker sensor should have magnet in it.

could you not just use the pickup that came with the acewell and use a magnet on the rotor?
 

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Discussion Starter · #12 ·
I could just use the acewell sensor on the front wheel. I was using it for a while, but it was kind of sloppy, and didn't work very well. I had to rebuild my engine last year, and while it was out I drilled the countershaft so I could add the 2nd gen bandit sensor. After buying all the stuff to make the stock sensor work I really want to figure out how to hook it up.
I think I might pop the sensor out and hook it up to test like the book says, only use 6v instead of 12v. if I can get it to work like that I should be able to get it to work in the bike.
Time to go get some resistors!
 

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Discussion Starter · #13 ·
I stopped by radio shack to pick up the resistors required for the sensor test. I also snagged a 6v battery while I was there. The plan is wire up the test circuit, test on 12v, and then hook it up to the 6v battery and see if it still works with the lower voltage.
I did just that, but found that my sensor is not even working with 12v hooked up! After checking and double checking my connections I have come to the conclusion that I have a bad sensor, whether I fried it or it came to me like that. I will have to grab another one from somewhere and resume testing then.
 

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Discussion Starter · #15 ·
As far as I can tell, I tried to do it exactly as the busa diagram showed. Hooked a wire coming from B/R over to B with a 10k ohm resister in line, and connected lead to the positive of battery. Ran a separate wire from B/W to neg of battery. Test leads to either side of the in line resistor, waved a screw driver all around and volts were always at 0, never changing. I tried testing at a couple different ways too, with no result. If I messed up somewhere please let me know, it took me a while to figure out exactly what the book was talking about.

I have been hooking up wires left and right to this sensor trying to get some reading. It wouldn't surprise me at all if I un-knowingly fried it at some point in time. I am trying to track down a cheap sensor to try again, or maybe just one I can test on to see if it will work on only 6v.
 
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