from Max
All of the energizing and de-energizing of the three solenoids required will have to be done through electrical circuits. First, before I begin, I'll have to add one more solenoid, as there is only a double solenoid set up on the bike, which will work just fine for second and high. This is how I'll wire it up: I'll run a hot wire back to the area where I manipulate the switches for starting. It'll have a toggle switch where I can energize the solenoid for low gear. There'll be a switch, as before, for second and high; however, when you shift to second, not only does the switch energize the solenoid for second gear, but breaks the circuit to the low gear hot lead. The delay needed to get low gear disengaged before second gear engages should be controlled by the shafts of the shifting forks, if I understand how they work. As soon as low gear is out of gear, or nearly out of gear, i.e., the pin out of it's slot, this will allow the already pressurized cylinder for second gear to actuate the shift. The set up as it is with the dual solenoid will work fine. Switch up, second gear solenoid energized, simultaneously breaks circuit to low gear solenoid, switch in neutral position, no circuit to either second gear or high gear, all pressures relieved on all air cylinders. Switch in the downward position, solenoid energized on high gear. As you say, you'll be able to put the bike in neutral by centering the second and high gear toggle switch. One feature that we gained is that we can easily start the bike in the pits and not worry about it being in or out of gear, and it will also keep us from putting the bonnet on when it isn't in gear, requiring us to pull the bonnet to put it in gear, which has happened several times. I like that feature. Now I've got to find a suitable solenoid valve for low gear, and of course, find a place to put it.