The Craftsman Walk Behind Mower 917.370910 is a self-propelled, gas-powered lawn mower with a 22-inch cutting deck. It offers variable speed rear-wheel drive, and can be adjusted to 7 different cutting heights. It's capable of mulching, bagging, or side discharging grass clippings, and features a foldable handle for compact storage. This page provides detailed information and instructions for repair and maintenance.
@jefftodd for a 917.370910 the Sears recommended plug is a Champion RJ2YXLE gapped at .030"
Briggs and Stratton uses the B&S 591868 which is a Champion RJ19LM (868). Either one of those will work. Yes, others too for as long as they cross reference to the Champion plugs.