losing spark??/

[Master LTR450]

ok my 400ex has spark one minute then the next minute its gone? Any ideas other than the boot being loose?

[babiak400ex]

This is what clymer service manual says.
If spark appears weak, or fires inconsistently check the following areas for possible cause:
A. Fouled / improperly gapped spark plug.
B. Damaged / shorted spark plug lead and cap.
C. Loose connection in ignition system.
D. Damaged igniton switch.
E. Dirty / shorted engine stop switch.
F. Damaged neutral switch.
G. Damaged coil.
H. Damaged ignition pulse generator.
I . Damaged ignition control module.
Hope this is some help.