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?
How did the plug look? Was it tan coloured or darker? If it's not showing signs of running hot (white instead of tan coloured), it's likely suitable.
Generally speaking, low revving engines operating in cool/cold conditions might benefit from a slightly hotter plug if fouling is an issue.
Good to know it's fine.
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.