iHave2Cams

i have a 75 shot of zex on my b18b, i do not have colder plugs, and i WAS running 87 gas, and i checked my plugs today after running a tank and ahalf of 94 octane gas, could the detonation on my plugs be from the old 87 gas or still from the 94 gas??? by the way, my timing is retarded 2 degrees.


thanks