For the original poster, see here for some great info from a pro and an easy process for checking all ignition components. (Post #36)
http://www.rcuniverse.com/forum/gas-...rmation-2.html

For earlwb: I don't understand the "pull up" resistor in your diagram. I know just enough about electronics to be dangerous, but it is fun to make simple circuits.

Truckracer: Yeah, those two ignition testing tools from RCEXL are cool and very handy. Makes setting timing a breeze too. (You don't have to get a whole ignition system set up to do so.)

Thanks,
AV8TOR