Lopi NorthField GSR2 Deluxe Owner's Manual page 51

Optional Equipment
3 Follow the directions below to replace the orifices.
1/2" Wrench
Rear Burner Orifice
Front Burner Orifice
Use a 1/2" open end wrench
a
to unscrew the two orifices.
Screw each LP orifice in so the
orifice protrudes 15/16" (24mm)
(indicating full insertion).
15/16"
24mm
© Travis Industries
c
4160713
(for qualified installers only)
b
Apply thread sealant to the LP
orifices prior to installation. Use
the chart below to identify the
correct orifices.
Look here for the orifice identification
NG
Front #54
Rear #52
51
LP
#64
#58
100-01442