The irritating speedo limiter

[casal-fan]

Until now, think the best solution found is Louis, with  the operating switch.
Louis also charted how the limiter electronically regulates the PV servo, so that it closes the PV when the CDI decides that: OK, this guy is having just a bit too much fun here, lets throw a bucket of cold water in his head.

So, the servo controler, inbuilt in the CDI, at least on the -00 models, is in the end responsible for the restriction.
If the servo control unit works in similar ways as the 3MA or RD for that matter, inputs to the servo are current and rpm signal...

Logic would be that the CDI in the 3ma, is adjusting the rpm signals to the servo.

Now, why not bypass the CDI?

Yamaha servo controlers are cheap as peanuts, I´m sure a lot of yamaha 2stroke rider have a couple laying around.
Why not use one of those? they can even be programmed.

Current or power input can be taken from many places (unsure, 5V or 12V), and rpm signal... well, on the 3MA, signal to the tacho is directly from coil current input... so maybe that could work?

This would bypass the limiter, by replacing the hardware that is limiting...
Nerdy, yes... but for track bikes, it would be neat to be able to ditch the speedo, speedo cable, parts that do not contribute to go faster

Tell me what you think guys.

[tzr-v4]

So, the servo controler, inbuilt in the CDI, at least on the -00 models, is in the end responsible for the restriction.
If the servo control unit works in similar ways as the 3MA or RD for that matter, inputs to the servo are current and rpm signal...

To use a 1KT or 2MA servo box you need to check how many wires on the 3MA servomotor => should be 5
 - 5V
 - 0V = GND (ground)
 - Motor 1
 - Motor 2
 - servo position sensor (output froml the servo => input for the CDI

Logic would be that the CDI in the 3ma, is adjusting the rpm signals to the servo.

No the CDI is not adjusting the RPM signal to the servo motor. CDI is powering the servor motor :
 - Wire Motor 1 = +12V / Wire Motor 2 = GND => YPVS is opening (or closing)
 - Wire Motor 1 =  GND / Wire Motor 2 = +12V => YPVS is closing (or opening)
The CDI compares the servo position sensor signal to the expectation according to RPM

ATTENTION : you need to check the tachometer signal (usually orange wire) to verify is it is the same shape between 3MA and 1KT. From memory :
 - 1KT is +200V when spark occurs
 - 3MA is -200V when spark occurs

So no change to run 1KT black box on 3MA !!!!

[casal-fan]

Hi Olivier
Pre de tout, felicitacion pour le titre. C'etait mérité

Olivier, on the 31k lc2, there are 3 wires from CDI to PV control unit.
I assume +and - , and the other one some kind of rpm signal.

Many years ago, i had to get digital rpm signal from a 31k engine to power and rgv tacho.
I got the signal by steeling watever is in the black yellow Wire shown below.

This is why i thougt IT could work. Giving the rpm signal to the controller, then i thougt the sservo control unit would take IT from there and give voltage to the potentiometer in the servo motor acording to what the servo controller is programed to?

But, this is just what i thougt possible to do, and i have tanken rpm signal from CDI to PV control to feed an rpm counter...
What do you think Olivier?

[tzr-v4]

Hi Olivier
Pre de tout, felicitacion pour le titre. C'etait mérité

Are you talking about soccer !!! I don't care 

Olivier, on the 31k lc2, there are 3 wires from CDI to PV control unit.
I assume +and - , and the other one some kind of rpm signal.

Many years ago, i had to get digital rpm signal from a 31k engine to power and rgv tacho.
I got the signal by steeling watever is in the black yellow Wire shown below.

From memory the 31K has a mechanical tachometer so the wire from the CDI routed to the dashboard.

According to the diagram.
YPVS box has :
- +12V => Br wire
- GND => B wire
- Kill switch or key => B/W
- RPM signal from CDI => B/Y

ATTENTION : you need to check the 3MA tachometer or coil signal (usually orange wire) to verify is it is the same shape between 3MA and 1KT-2MA-31K-1WT-47X. From memory :
 - 1KT shape is +200V when spark occurs
 - 3MA-2XT-2YK is -200V when spark occurs

So no change to run 1KT black box on 3MA !!!!

[tzr-v4]

Another image from TDR250 2YK CDI

White trace => orange wire -200V pulse at each sparks (5V/Division and probe set to x10)
Green trace => signal going in the CDI IC after some electronics filtering square wave 0V -> 5V

On 1KT or 31K... White trace will be the other way =W +200V pulse

So the 31K YPVS Box will not like the pulse.

[casal-fan]

Ok Olivier, think i understand.
The problem is to find a suitable rpm signal to the PV control box.
31K or 1kt Has different signals then 3ma

Do you think there is a possibility to easily chance the signal from +200 to -200?
I understand that this is Perhaps a stupid question, but please understand that I have No knowledge about electronics.

Also, i have the impression that you reserach a Lot about 2strokes.
If you have knowledge about other 2strokes that use -200V to feed the PV controller, it would be nice to know because i have at least controller and servos for RG, rgv, mito, etc etc.
Also, later 3ma models had external PV control, maybe one og Thise would Work.
Have to check wiring on later models.

I really would like to dump the speedo with All the stuff that comes with it, and make my 3ma a only race bike.
Race bikes dont use speedometer

Cheers
Rui

[tzr-v4]

I've been working and looking on 2 strokes Yamaha only bikes.
So I can't help on other makes.

I've designed a RPM converter which could transform -200V or +200V pulses to square wave in 12V or 5V.

Electronic board applied to DTR200 bike to have an electronic dashboard (tachometer).
http://ypvsbox.free.fr/?p=966

3D printed box
http://ypvsbox.free.fr/?p=974

So maybe, we could hack the 31K YPVS box to plug the output of my RPM-Converter on the board.
But as I don't have at the moment TZR250 2MA or RD500LC 47X running bikes I can not test.

I'll try to borrow a TZR250 1KT with a RD350 YPVS box to do some testing.
I'll be in holiday away from the workshop from 25/07 to 05/08 

I've run a batch of RPM-Converter PCB so I could setup 15 kits for sale (not to make myself rich  )
Before selling any stuff, I need to do more testing.

Olivier.

[000nicec]

Strip the speedo and Drill a hole a the back of the of the dial and put a pin to stop speedo needle going past point of break down. Wont get a speed reading but bike should keep going.....

[Louis]

Yes that is correct
The metal tap needs to be seen when starting the engine, when metal tap is leafing the optic's when speed increase you have full power.
If you reach about 180kmh the metal tap comes again between the optic's and it start closing the ypvs.

When you make sure the needle stopping before it hits the 180, you will keep full power.
Can you not stick a small universal digital bicycle speedo meter on your bike?, they are easy to mound

[000nicec]

That's what I would do...Easiest ooption

[jools]

You could fit an MPH speedo converter as you would never see 180mph on the bike? .
I have an MMax box fitted but would prefer to remove the speedo entirely.

I await the replies to fit a Zeeltronic with anticipation...

Jools

[ColinS5940]

....or you could buy a nice set of fzr600 clocks and swap the dial and gear over, looks far tidier.