Originally Posted by
mthird
How much runtime are you getting out of your plugs? I've on my third one through seven gallons on my B5. I used to go burn them up every few tanks until I learned to tune a bit better.
I replace my plugs at the gallon mark on any engine, not because they're done, but because I don't want one to have one go bad in the middle of the main. Changing plugs every gallon is good preventative maintenance.