94 L model, 6000 miles, original plug, I think. Right now I have a stock carb with dynojet kit with a 160 main, needle supplied by them with a E series muffler at 5 disc. ON the E, the less disc the richer, more leaner, so instead of changing jets this would be the easiest to do first. Now I'm at about the richest disc setting the E will go, so of course if I get a reading of too lean, then it's jet time. 1) to do a SP chop reading should my plug be brand new ? 2) should it at least be cleaned 1st ? 3) so at idle, I simply leave it idle for a few minutes and check it? 4) what throttle postion would give me the needle reading, if I should raise,lower or leave where it's at ? Mid throttle ? 5) main jet I floor the thing in say 3rd gear, kill it, coast to stop and check ? Do I do top rpm in 3rd and kill it? 6) when it's real hot and humid out, would jetting be richer ?