I don't know Joe, I used the little spring that came with my DL until it fell out and I lost it. It should provide the same connection as clamping but I ain't no expert. Been running without it for almost a year now without a single glitch. The engine I was refering to above was a G26 converted to EI and after installing the bonding wire back to the CDI box the glitches went away. We tried clamping the plug shield (that usually works) but no joy this time. The radio in that case was a JR 72 mhz 7 channel and the receiver that came with the radio. Also the metal braiding on the plug wire was in perfect condition.