THUNDER TIGER TOMAHAWK BX Manual page 11

15 ENGINE BREAK-IN
For a new engine (break-in setting), the high speed needle needs to be set as rich as possible. Turn the high speed needle 1/4
turn counterclockwise from initial setting (3~3.5 turns from fully closed). Repeat step 15b. Keep doing this until the engine stalls at
full throttle, then turn the high speed needle 1/4 turn clockwise. Run the car in an open parking lot with this rich engine setting for
at least 5 tanks of fuel to complete the break-in process. It is normal for new engines to stall many times during this time due to the
rich setting. When it does, just restart the engine. After break-in, follow the engine setting procedure to set the carburetor for normal
operations.
5
ENGINE SETTING
Due to different fuel formula, operating elevation, humidity . . . etc. The engine may / may not operate properly at initial setting.
Please follow the following procedure to achieve proper carburetor setting. Do not perform this procedure until the engine has been
properly broken in.
a. Start the engine.
b. With a running engine, run the car back and foreth in a straight line (full throttle achieved during each passage) in an open parking
lot. Repeat, and note the sound of the exhaust. Do not hold the throttle open with car off the ground or the engine connect rod
may break.
c. If the exhaust does not reach a high pitch note, turn the high speed needle (long needle, extending from carburetor, pointing up)
1/4 turn clockwise, and repeat step 15b.
If the exhaust reaches a high pitch note immediately, turn the high speed needle 1/4 turn counterclockwise, and repeat step 15b.
d. Repeat step 15c until the engine reaches optimum setting (turning in the high speed needle will no longer have an effect at full
throttle and turning out the needle will cause the engine's full throttle rpm to drop a little).
For normal operations, turn the high speed needle 1/4 turn counterclockwise from the optimum high speed needle setting.
e. To set the idle, turn the idle screw in (higher rpm) or out (lower rpm).
Basically, the idle needs to be set at the lowest possible point before the engine stalls.
f. To set the low speed needle (larger needle on the side of carburetor body), the engine needs to be broken-in and high speed
needle needs to be set first.
g. Repeating step 15b every 10 seconds (1 second of full throttle and 10 seconds of idle). If the engine rpm at idle drops after a
few seconds and stalls, then turn in the low speed needle (clockwise) 1/4 turn. If the engine rpm stays the same or goes up at
idle, then turn out the low speed needle (counterclockwise) 1/4 turn.
h. Keep repeating step 15g until the engine rpm drops (goes to idle rpm, then drops a few more rpm after a few seconds) but does
not stall at idle.
a.
b.
c.
d. 15b 15c
e.
f.
g. 15b
h. 15g
1/4
1/8~1/4 15b
1/8~1/4 15b
10
1/8
3~3.5 1/4
1/8