[MetroMPG]

I can't really help with the fine tuning of the timing - you've got a jumper set somewhere in order to change it, right? The Flea doesn't have anywhere to set that jumper, so I've only ever set the timing by ear.

If you want to know what pinging sounds like, just set the timing waaaaay advanced, and load up the engine (accelerating in a high gear would work). It'll sound like there are marbles pinging around in the cylinders.