0.030" for a champion or 0.020" for NGK and others.
official site for Briggs and Stratton Spark Plugs is: http://www.briggsandstratton.com/maint_repair/routine_maintenance/choosing_spark_plugs/ The proper spark plug will depend on the type of 6.5 HP motor that you have. Briggs and Stratton made several different ones and the best way to get the proper plug will be to call an authorized Briggs and Stratton repair shop with the mower make and model numbers.
what plug size fits a 3.75 briggs and stratton,and a 19.5 briggs engine and what is the gap. thank you
briggs and stratton motor, autolite 3924 plug
The proper spark plug for 4hp Briggs & Stratton is a J8 which I use in all my motors.
Champion RC-12YC at 0.030"
what is the champion cross reference for a briggs and stratton spark plug 691043
0.030 is the gap for briggs and stratton 4.5 hp mower
Champion RC12YC or E3 Diamond Fire E3.20
.030
Rc12yc
.030
Champion RJ19LM