Scootnfast's Scooter Center

UPDATE: 12/16/08

This article has been pretty much made obsolete thanks to Fast Trails Performance. They are the first to create and currently the only ones with a three phase drop in stator. This stator is a direct replacement for any horizontal motors stator and allows you to simply bolt it on and plug it in to the MadAss wiring harness. You no longer need to alter your factory wiring... AWESOME! You can find the new three phase stator here.

Disclaimer:

1. Let me first start with the fact that I am NOT a mechanic. I have been working on motorcycles and scooters for a long time and know a little about what I am doing. I simply take pictures for other people to use as a guideline to help them modify their own motors. Any modifications you perform are done completely at your own risk and liability.

2. Tampering with your motor in any way may void your warranty. Make sure this is a sacrifice you are willing to make before you begin working on your own vehicle.

3. Before you begin, read this ENTIRE article from start to finish so you know exactly what is involved and what steps are required to properly complete the procedure. Also make sure you have a nice clean area to work in.

4. This example was performed on a 2006 Sachs MadAss 50cc automatic.

5. ALL bolts and socket head cap screws are in metric! Don't try to work on your vehicle if you don't have metric tools, you will just wind up messing up the heads.

Well, without a doubt, the most difficult thing with our motor upgrade and conversion was the wiring. Reading all over the internet, and listening to all the problems people had run into in the forums, we knew we were going to be in for a headache. But that is OK, we suffer the headaches so you don't have to.

I want to start by giving you some background / insight / heads-up as to why there is such a problem with the wiring.

First and foremost, most dirt bike, pit bike, 4 wheelers, ect. running horizontal motors are typically powered by an AC single phase stator. The MadAss uses an AC three phase stator.

Second, everything on the bike is powered and operated off of DC current. Most other horizontal motors run AC lighting and CDI units. The MadAss actually has a very large DC rectifier that converts that 3 phase AC current into a lot of DC power to run everything on the bike including lighting, accessories, ignition and charge the battery.

A typical horizontal motor stator setup has 2 separate coils, one to power the ignition and one to power accessories. However, the accessories are usually powered by AC power, not DC. On motors with electric start, there is typically a rectifier included, but this is usually used to just keep the battery charged for starting. The lighting and other accessories are still powered by direct AC power supplied by the stator.

So, the issues we ran into were:

1. How are we going to swap a single phase unit for our 3 phase system.
2. How are we going to generate enough power to run all the accessories in DC current since really no stators available for these types of motors generate that much DC current with what is available on the market.

Lets now show you a diagram of the MadAss Wiring

Some things to take note on are, notice that there are only 4 wires coming from the motor... 3 yellow and a blue/white. The 3 yellow are the three legs of the 3 phase AC power, and the blue/white wire is the spark pulse ignition signal wire.

Also notice that the kill switch grounds the pulse wire for the ignition hence killing any chance for a spark.

Now take notice to the fact that the CDI box only has 4 wires instead of a typical 5 wire CDI.

And the last key thing to notice is that the ignition switch in the on position actually turns on the positive lead for powering the CDI box and give the rectifier a positive signal.

Now lets look at a diagram for a typical horizontal motor wiring:

Now you can see that there are 2 separate coils, one for ignition power (Black/Red) and 2 for the AC accessory wiring. The yellow is the "Hot" wire and the white is the neutral wire. You can see that there is a branch off the yellow wire where accessories are run off the AC power. Then the White and Yellow wires go into the rectifier. This set-up is for electric start motors and simply generates enough power to keep the battery charged for starting the motor. It is not meant and is incapable of powering accessories with heavy loads.

Also notice that the kill switch does not kill the pulse signal, but instead kills the CDI box. This is done by grounding the CDI out, where the MadAss turns the CDI on with a +12V signal. Also notice that the ignition isn't really designed for use with a key switch. However, that is easily overcome. The tricky part was being able to kill the motor with the key switch which only sends a positive signal, but the new motor CDI requires a ground signal.

To fix this problem, we added a relay that is normally closed. We are relaying a ground signal to the CDI to kill it. When the key switch is turned on, power is sent to the relay, lifting the contacts which breaks the ground to the CDI enabling it to run.

Now we tried a few stators and a few rectifiers. We found the best solution was the set up offered by OO-Racing. Their stator kit has a large rectifier capable of outputting the power we need to keep the bike running tops. This kit is pretty much exactly like the diagram shown above, but instead adds a 5th wire going into the rectifier. This is to turn on the rectifier and monitor the voltage so it can increase the output if the voltage drops from heavier loads as accessories are turned on.

OK, so after all of that, lets show you how our current wiring diagram looks like: