Champion RCJ-6Y
.030
0.025 in gap (0.63mm)
on most trimmers the gap is about 25 thousands !!
Champion RCJ-6Y ... per the Manual.
Spark plug gap should be .025 http://store.chainsawr.com/
anywhere between 16 and 18 on a spark plug gauge should work fine.
The Sear's website recommends spark plug number DJ7Y, but the brand is not listed.
.030"
.03
The replacement is a Champion CJ-8
You can cross reference a RC12PYP3 or RC12YC non-platinum spark plug for a Briggs 696798. The Briggs Platinum 696798 spark plug is for a snow blower. Part number 696020 for a Platinum plug from Sears is an equivalent also.