i am running a msd box for the six with a new coil, fresh wires, but the motor cuts out , but not comepletely under load at about 4000-4500 rpm and does the same in the the rest of the gears...the motor will run though this hesitation, and after pulling past that rpm resumes normally to full throttle....i am not sure if it is vacuum related....or msd related.....so how do i check out the box?

usually my silly quetions are answered in minutes......hmmm
not many msd users out there????
anyone?....where o where is the cap'n , jp, brad......

We have always just sent the MSD boxes back to the factory and they check them out for you. Don't charge much either.

Matt

MSD makes a tester for their boxes and I bought one when I first got my unit. It will simulate running the engine up in RPMs and has a spark plug that will show the spark. The second tool I have is a Snap-on spark voltage checker that clamps over the plug wire at the plug and will give the actual voltage at the spark plug. Both have been invaluable for checking mine and others ignition systems. Otherwise you could find someone and swap boxes or just send it back.