Mat

Mat,

If you carefully study the excellent wiring diagram done by Jim Snell, you'll see that he has nicely divided the electrical system into two components, which most all newer (water-cooled) Trials bikes need. They need one to power the engine's electrical system, which you don't want to mess with except to wire a good killswitch to the white wire on the ignition control module. I like the Yamaha YZ killswitch as it's simple, reliable and doesn't stick out so a branch, rock or my flying body won't hit it. Mount the switch in the center of the handlebars below the crossbar. This, for three good reasons:

1) the wire will not have to move in a large arc and is less likely to be stretched and broken,

2) it's easily reached if the handlebar ends are mired in mud or brush and

3) it's a standard place for riders to put the switch so a bystander or checker will go there first when your engine is revving to the moon and you are sliding down the slippery hill side of the section. Be sure to turn the handlebars to the point where there is maximum stretch on the killswitch wire and add a little more so it won't bind, before cutting the wire to length.

Besides the ignition output side of the alternator, you need another system to power the fan. This consists of the yellow alternator output wire to the 12 volt AC regulator which "regulates" the voltage to 12 volts and generally no more. That 12 volts AC goes to the thermostat switch, which controls when the fan is needed to further cool the engine. When the thermostat gets hot enough, it closes the circuit running to the fan, however, that 12 volts AC then needs to be "rectified" to 12 volts DC so the fan can use it, so it is run through the DC Converter (or Rectifier" as it is also called, from the Latin "recti", meaning "right" or "straight"). From the DC Converter, it goes to the fan. All the rest of the wiring on the bike is not necessary for it's operation, you just need ignition and fan.

If you understand how the system works and carefully take your time, you should be able to figure it out. If you haven't converted a bike before I would recommend that you have someone with practical experience show you the first time. Check with your dealer as they can probably help. My Gas-Gas dealer, Harry's Trials Shop in Citrus Heights, California, was kind enough to set mine up completely before delivery, and it's always worked perfect. After you set up the wiring, always test it to be sure everything works. Let me know if you need more help.

Jon