What’s a plug chop?
:A plug chop is one way to verify your main jet jetting. To do a plug chop, make sure the air filter is clean, warm up the motor, shut it off and install two new spark plugs. Start the motor and pin the throttle, running through all 6 gears. When you wind out the top of 6th gear, hit the kill switch and pull in the clutch, keeping the throttle pinned. Remove the spark plugs (put in the old ones to get home if necessary) and put one in a vise. Using a hacksaw, cut the threads away from the center electrode with one cut parallel to the electrode and one cut perpendicular to the base of the electrode, so you can see the very base of the center electrode. If your main jets are spot on, you will see a 2mm tall chocolate-brown colored ring at the base of the electrode. If the ring is taller than 2mm or darker than a Hershey bar, you’re rich on the mains. If the ring is smaller than 2mm or lighter, or nonexistent, you’re lean on the mains. If both plugs aren’t almost identical, one cylinder m
