Troy-Bilt TB90BC Operator's Manual page 22

REPLACING THESPARKPLUG
Use a Champion RDJ7Y spark plug (or equivalent). The
correct air gap is 0.020 inch (0.5 mm}. Remove the plug
after every 25 hours of operation and check its condition.
1. Stop the engine and allow it to cool. Grasp the plug
wire firmly and pull it from the spark plug.
2. Clean around the spark plug. Remove the spark plug
from the cylinder head by turning a 5/8 in. socket
counterclockwise.
3. Replace cracked, fouled or dirty spark plug. Set the
air gap at 0.020 in. (0.5 ram) using a feeler gauge
(Fig. 44).
,_ CAUTION: Do not sand blast, scrape, or
clean electrodes. Grit in the engine could
damage the cylinder.
4. Install a correctly gapped spark plug in the cylinder
head. Tighten by turning the 5/8 in. socket clockwise
until snug.
If using a torque wrench torque to:
110-120 in..Ib. (12.3-13.5 N.m).
Do not over tighten.
0.020 in.
(0.5;_ _ mm)
Fig. 44
ACCESSORIES/REPLACEMENT PARTS
2-Cycle Oil .......................... 791-147543
Spark Plug ......................... 791-610311B
Exhaust Gasket ....................... 791-182065
Spark Arrestor ........................ 791-182747
Replacement Line ............... 0.105in ( 2,66mm )
Replacement Line Cartridge ............... 753-1160
Inner Reel Spring .................... 791-610636B
Outer Spool ......................... 791-683301
Inner Reel ........................... 791-147495
Bump Knob ........................ 791-180814B
Fuel Cap ........................... 791-180000B
Shoulder Strap ...................... 791-682075B
These replacement parts can be purchased from your
local authorized dealer.
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