Racing a 3EN2

[Evilchicken0]

The jap restriction - bike won't rev past 12,5k if the CDI thinks it's at 0mph. I knew a guy with an import TRX that would restrict on the dyno, I gave him a M-Max box and it was ok.

[willandrip]

The problem with the 3EN2 and the M-max box is that the box plugs in ,in series with the speedo wiring Boris;
I believe in this case the speedo has been removed in its entirity.
On 3Tj models;the box is fitted at the TCI end of the harness, on the 3EN2 it goes right behind the speedo head.
It may be possible to sacrifice a speedo head and butcher the wiring ;hopefully removing the need for the speedo drive completely,as yet I have no need to do so. Kayla may wish to do this at a later stage.
On other forums; contributors have stated some of the wiring in the box itself is redundant and blank tails with the corresponding plugs are in place to simplify fitting.If this is the case the speedo head may not be required at all.
I am in the process of this scenerio with one of the bikes at present.
No instructions for fitment have been forthcoming in the past or a wiring diagram of the unit itself despite requests.
One would have to presume the 3EN2 and 3TJ fitments are the same unit.The colours do not match the 3EN2 harness but the plugs certainly do.
It is a simple matter to plug it in but an idea of the internal components would be of considerable help.
I am reluctant to dismantle the only box I have currently.

[Evilchicken0]

I've seen one plugged into the cdi

[willandrip]

Was that on a 3EN2 though Boris?
There is only the 6 & 4 pin specific sockets on the TCI body.These two sockets must be ignored.
This leaves one tail that has the exup servo round pin socket and two seperates
One is green/blue tracer that goes to the derestrict in the speedo head and a red/ white tracer that goes ??????

The m max is 3pin socket/plug in & out and 1 single male/female/in/out. Photo missing !



This is possibly where a disassembled box would be invaluable.
If some wires are dummies then it may be fitted to the 2 single tails on the servo lead ;the wires may correspond.The 3 pin plug does not.

[Evilchicken0]

Yes it was on Phil Norton's bike

[willandrip]

Which leads us back to where we were last November;
viewtopic.php?f=37&t=39430&p=288357#p288357.

This topic has gone round in a circle without a definitive answer since about 2006 checking out the archives.
I await a second box and will dissemble one and work from there.

[Morespeedvicar]

So from my really ruff reading its restricted in nuetral and when the speedo is 0?

If thats the case can you measure the reading from the speedo wire stood and moving and disconnect the neutral switch?


Or am i missing something???

Cheers
Ian

[Kayla850]

So from my really ruff reading its restricted in nuetral and when the speedo is 0?

If thats the case can you measure the reading from the speedo wire stood and moving and disconnect the neutral switch?


Or am i missing something???

Cheers
Ian

This is the restrictor circuit-





I think that's a Hall sensor in the middle, the blue plastic thing is just there to mount it to the main speedo body.

For the ignition to work properly the following stars need to align, anything else will end up with the ignition defaulting to its restricted mode-

1. When you first turn the key, the ignition needs to get an electrical signal from the speedo. This is to check the four wires are still plugged into the speedo head.
2. When the bike starts moving, the ignition needs to see that the speedo needle is also moving- no removing the speedo drive cable to get around the top speed restriction.
3. There's a long metal tang on the back of the speedo needle hub that passes the sensor at normal driving speeds. I think this might just be a throwback to the 'speed' light that was on the Genesis.
4. There's a small pip on the needle hub that passes the sensor at 180km/h. This is what triggers the top speed restriction but in can be worked around using a speedo convertor.

An M-max or POSH box works by simulating the speedo circuit and giving a false signal to the ignition so you can remove the speedo head if you want to go faster than 112mph but don't want to keep the speedo connected (ie if you're racing or trackdaying the bike!)

Looking at it, it looks like a simple oscillating circuit might work. It'd provide the initial 'on' signal to the igniton but then would drop to zero to simulate the speedo needle moving, then back up to 'on' to simulate the bike stopping for a minute, then back to 'off'... repeat to fade...

[willandrip]

Sterling work Girl;getting there bit by bit.

On point 3; Will the metal tang passing the sensor begin the speed restriction cycle; will it signal to the TCI that the bike is no longer at rest.???

[willandrip]

So from my really ruff reading its restricted in nuetral and when the speedo is 0?

If thats the case can you measure the reading from the speedo wire stood and moving and disconnect the neutral switch?


Or am i missing something???

Cheers
Ian

There is no restriction at rest (neutral) It engages when speedo signals the bike has started moving and has exceeded a set speed (112mph) or if no start signal is received (no speedo fitted);this is why Dynos cannot give a accurate power reading. ( but this is for future use)
If the dyno was so configured that the front wheel was powered on rollers by the rear then the restriction would not occur.(until the 112mph limit was reached or circumnavigated by a speedo converter)
Fronts are usually clamped for safety.There are no front rollers.
In neutral or at rest the bike will rev till the engine rev limiter engages circa 14500/15000 .(or go bang)
This makes for difficult diagnosis; you do not want to be doing road tests with engine at 12,500 + even with clutch pulled in !
The neutral switch has no influence on the circuit. (as Kayla has discovered. )