Where is the signal for the speed sensor coming from?

[michalc]

I'm trying to make my own gear indicator for my FZ6 2007 and I'm curious about where is the speed sensor signal coming from. Based on the values I measured, it looks like one driver sprocket revolution makes ~25 speed sensor pulses, so I guess it measures 5th gear wheel (25 Teeth) or 6th gear (26T).

 

[Motogiro]

You're measuring pulses at the ECU? Black with blue tracer, white with yellow tracer, and blue wires.

2007 Yamaha FZ6 (FZS6W) Electrical 1

Shop online for OEM Electrical 1 parts that fit your 2007 Yamaha FZ6 (FZS6W), search all our OEM Parts or call at 252-758-3084

www.ronayers.com

#12 on the parts fiche.

 

[michalc]

I measure it between the speed sensor and the ECU on the white/yellow wire that goes to the ECU (grey/black wire in my connectors).

Here is an example of one measurement and calculations based on the measured values. https://docs.google.com/spreadsheets/d/1CTUoz5wI2Gc5jbdXTFMje7L4pIehY9S3jBUjTd0tXvw/edit?usp=sharing
I highlighted the the constant I mentioned before (the estimated 25 pulses per revolution)

 

[michalc]

I've done some research (check the image), but I'm still not sure, what sprocket the speed sensor scans. I've also found this video:

 

[Motogiro]

Did you look at the link in my #2 post? The speed sensor is located in the general proximity to that area of the bike depicted, which could also be on the other side of the bike. I'm hoping that might help in discovering what that sensor is reading.

2007 Yamaha FZ6 (FZS6W) Electrical 1

Shop online for OEM Electrical 1 parts that fit your 2007 Yamaha FZ6 (FZS6W), search all our OEM Parts or call at 252-758-3084

www.ronayers.com

 

[michalc]

Yes, I saw it, thank you for the link. I'm attaching images from my previous post, because they are there in a bad resolution. I think the location is clear from these images, but still I'm lost.

 

[Andz]

It seems a bit illogical to take the speed from anywhere except one of the wheels, what happens if you do some radical regearing with the chain and sprockets? The speed sensor inside the engine isn't going to know that.

 

[michalc]

If you change the driven or driver sprockets' number of teeth, obviously the speed sensor will measure badly, but in this case I believe even the original FZ6 display will display wrong speed.

 

[TownsendsFJR1300]

It seems a bit illogical to take the speed from anywhere except one of the wheels, what happens if you do some radical regearing with the chain and sprockets? The speed sensor inside the engine isn't going to know that.

The stock speedometer reads high (like most bikes) to start with. Nothing a "Speedohealer" can't fix:

https://www.healtech-electronics.com/products/sh/?v=58e69a293e3d

.

 

[Motogiro]

It seems a bit illogical to take the speed from anywhere except one of the wheels, what happens if you do some radical regearing with the chain and sprockets? The speed sensor inside the engine isn't going to know that.

That's the way it was done in the past. Usually from the front wheel. Then a speedo cable went right to the speed readout. Same with the RPM. Used to come off a gear on the cam.
The speed now is off output of the transmission then to the ECU where it is calculated, sent down a data line to a CPU in the instrument cluster and then the readout.
This does mean that re-sprocketing will change speed indication which is not accurate on Japanese bikes to begin with. No reason for the speed indicated on a stock bike to be inaccurate to begin with.
My thought is that whatever gear the sensor (hall effect?) is reading, is going to be a gear or rotation that is a constant with the output shaft.
So to make a gear sensor we should be able to calculate output shaft rotation to rpm at the crankshaft position sensor.

 

[Andz]

The stock speedometer reads high (like most bikes) to start with. Nothing a "Speedohealer" can't fix:

https://www.healtech-electronics.com/products/sh/?v=58e69a293e3d

.

I had a look at that site but what's not clear to me is if the Speedohealer is attached for calibration then removed, or becomes a permanent fitment on the bike.

 

[TownsendsFJR1300]

I had a look at that site but what's not clear to me is if the Speedohealer is attached for calibration then removed, or becomes a permanent fitment on the bike.

It's plug and play. You can simply un-plug and put it on another bike(with the same harness)

For mine, I used my GPS to find the true speed, then adjusted the healer to adjust for reading low.
My speedometer is NOW within .1 MPH (dead nuts on) .


Another feature it has, it will /can record your top speed and save it. Just push the button to erase it.
This, ^^, is simply a plug with button you don't even have to plug into the unit.. If say, it's your kids bike and you want to know his "riding habits" you can.

They may have updated it, mines at least 10 years old, never an issue.

.
..

 

[Andz]

It's plug and play. You can simply un-plug and put it on another bike(with the same harness)

For mine, I used my GPS to find the true speed, then adjusted the healer to adjust for reading low.
My speedometer is NOW within .1 MPH (dead nuts on) .


Another feature it has, it will /can record your top speed and save it. Just push the button to erase it.
This, ^^, is simply a plug with button you don't even have to plug into the unit.. If say, it's your kids bike and you want to know his "riding habits" you can.

They may have updated it, mines at least 10 years old, never an issue.

.
..

Thanks but it isn't clear if it needs to stay on the bike, what I am asking is if it is possible to borrow one to calibrate then disconnect it.

 

[TownsendsFJR1300]

Thanks but it isn't clear if it needs to stay on the bike, what I am asking is if it is possible to borrow one to calibrate then disconnect it.

You cannot change what the stock speedometer reads, (W/O some sort of add on "adjuster") period...

The SH takes the signal, you adjust it for higher/lower to your bikes need. It stays on the bike if you want it to adjust the signal..

Just curious as to why you wouldn't leave it on??

.

 

[Andz]

You cannot change what the stock speedometer reads, (W/O some sort of add on "adjuster") period...

The SH takes the signal, you adjust it for higher/lower to your bikes need. It stays on the bike if you want it to adjust the signal..

Just curious as to why you wouldn't leave it on??

.

I thought I could get away with not buying one if I could borrow one from a friend. Scottish blood!

 

[Motogiro]

I thought I could get away with not buying one if I could borrow one from a friend. Scottish blood!

LOL!