How can you tell if you've got spark knock on a carbie? I am hearing some ticking at about 3 on the tack at WOT... I think it might be the rocker arms (I haven't set the valve lash yet)... I am going to set the lash and fill up with some better gas, and hope that it goes away...

 

The best way I can describe "ping" is that it sounds like a bunch of marbles are rattling around inside your engine. It is not a constant "tick" or anything like that; it is more "erratic". If you back off the throttle, it should disappear immeditately.

It happens usually under "high load" conditions.

 

Detonation will show up on the sparkplug insulators as blackish flecks (little fly turds).