My 99 900rr's fan doesnt seem to kick on till around 221 degrees. Out of fear of ruining the engine from the heat I decided to add a manual fan switch.
What you'll need..
10 inches of wire (Bigger is better. I used scrap 12 gauge from different project.)
1 wire tap-in
1 small washer
1 toggle switch (Any switch will do. Mine was 3 bucks at radio shack.)
Honda screw driver & hex wrench
1) Unscrew quick release screw from top of middle section faring.
2) Unscrew 2 hex screws on black plastic thingy under left handle bar.
3) Drill a hole about 2 inches from screw hole closest to tank.
4) Fit switch by removing the nut from around switch. thread into hole you just drilled. re-install nut.(Tighten nut hard as possible as this particular faring is exposed to vibration.)
5) Cut 10 inch wire into 2 parts one shorter than the other. (8/2 is what i used as the switch isn't to far from where ground is located.) strip both ends.
6) Find the fan switch wire coming from the front of the radiator (bottom left). follow that wire around and place wire tap-in on that wire around where the switch is above(basically half way up that black wire, cut away plastic covering so it looks nice). now place one end of longer wire into tap in and crimp it. connect other end of that wire to switch directly above. if you don't have the proper wire connectors wrap in electrical tape so it doesn't short out.
7) Connect one end of short wire to switch and the other to the faring mounting hanger jutting out from where tank is. put the washer on it to keep it in place. now re-stall faring. make sure to give the bolt where switch is grounded to is extra tight because of vibration. dont forget to reinstall quick release screw from middle faring.
Done. Switch will only be functional when ignition is turned on. So if the keys off the fan wont drain the battery.
By adding a switch to the fan wire you by-pass the thermostat control of the fan. the fan will still switch on when its suppose to, but you have the option to flip it on to keep temps lower.
Extra note. As it turned out my wire tap-in for 18 to 20 gauge wire not 12. it still connected good but it was a tight fit. I wrapped a little electrical tape around it to keep the protective plastic piece closed.