The threads on the Champion RZ7C plug in the G26 are too long, the piston might hit the side electrode...The CM6 plug in the engine is not a resistor and there are no short resistor plugs..
A fix would be a shielded cap from C&H, DA, or 3W that fits the plug, but the mag might not be strong enough to fire a resistor plug, and the shielded caps have a built in resistor...
Or you might get by with a spacer under the resistor plug if the mag wire is long enough...
A CDI ignition would save much weight and would work, but the cost might be more than you want to pay....
You might try a new CM6 and aluminum foil around the plug and wire, all the way back to the mag coil...Secure it with some tie wraps...