Ignition Kill Box.

[jimr1]

Hi guys, I need to build an ignition kill box for a friends drag bike.
I have an OK understanding of electronics, i.e. what I need to be able to achieve my goal, but I don't understand the nuances.
On the ECU of the bike is a +B pin/lead that goes to the coils, basically a signal pin, now what I plan to do is make a monostable 555 with a p-channel mosfet to interrupt this signal from between 50-100ms.
Eventually, in the future, when he gets an air solenoid for the gear shift, I will be modding this to cut the ignition for 15-20ms, then activate the solenoid (5-10ms for it to shift) then leave it another 10-20ms before putting the ignition back on, I'll want all these latencies to be adjustable.
Now the rather embarrassing question I have is what values of components to I need to enable this 50-100ms signal from the monostable. I would LOVE to have a led readout of the time, but this can come in the future when I'm a bit more familiar with what I am doing.
I never was any good at figuring out freq/pulse times on 555's, mental block I guess.
So, what I need to know is what cap/potentiometer do I need?
Regards
Jim.

[stealth17]

I'm confused on what you are trying to do. Are you just trying to add a kill button to stop the motor/?