There are several ways to "kill" a cylinder. If you have vaccum petcocks you can run on prime, unhook the vaccum line to "kill" one side, the plug on the other side.
Make an adapter that threads on the plug that you can put the plug cap on and use a jumper wire to ground the plug.
Take a wire, strip off a few icnhes of insulation, wrap this wire around a plug, a clip on the other, clip the wire to an engine fin, plug the plug into the plug wire you want to "kill".
Pull a plug, plug on the wire, have a freind hold the plug to the engine while you do the tuning.
Leo
Make an adapter that threads on the plug that you can put the plug cap on and use a jumper wire to ground the plug.
Take a wire, strip off a few icnhes of insulation, wrap this wire around a plug, a clip on the other, clip the wire to an engine fin, plug the plug into the plug wire you want to "kill".
Pull a plug, plug on the wire, have a freind hold the plug to the engine while you do the tuning.
Leo