Wrong plug?

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Mar 24, 2007
Upstate NY
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.
For years now, I have been using the J19Lm plug in all the flathead B+S and Tecumseh engines I work on, and they have never caused a problem.
The old plugs were J8C.J19LM is fine,but I find the EZ Start plugs better.
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.
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.
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