Spark Plug gap is .025
.25=
Champion RDJ7Y is the correct number.
Mine has original plug, it is a: Champion # CJ8Y
0.020 in or 0.50mm
.030
.030 Champion RJ19LM
.030
My 16" Craftsman 36 cc chainsaw manual calls out for a Champion RCJ7Y....if that is the same size chainsaw as yours, I would go with that plug.
Spray some ether in the carb. If it fires, it has spark, but not getting fuel. start there.
About 1/8 inch is close enough
Most snow blowers have the spark plug on top of the motor :to change a spark plug you get a spark plug wrench (take wire cap off the plug) put wrench on spark plug then turn counter clock wise to take it out. To put a new one back in reverse the proses
.030"
.030"