[HawgRyder]

Pre ignition or "pinging" is mostly caused by either too much ignition advance...or too low an octane in the fuel (for the compression factor of the engine).
So...the fixes are....lower the compression (expensive)
...retart the timing (easy..but might lose some power...and build more heat in the engine)
..#3...buy better gas (petrol)...
Sometimes a little fatter on the carbs might help too (richer).
Good luck.
Bob