My old Ariens snowblower has a 4 hp Tecumseh HS40 (old L-head design) powering it. I checked the plug today, and it's a Champion J19LM. It's supposed to be a Champion J17LM. Will the slightly hotter plug affect anything?
The insulator looked fairly dark. Not sure if it's fouled or not. A new one is $3, I may as well since the machine wasn't running right when I first got it, and the plug came with the machine.
Put in a new Champion EZ Start 5861 (J19LM and J17LM compatible according to Champion). Much easier time firing up and got off choke faster. Glad I did it.