Adjusting The Power Adjustment Screw; Idle Speed Adjustment; If Your Engine Won't Start; 7 Hp Engine Carburetor - Troy-Bilt Horse Owner's Manual

114
On the 6 H.P. engine, it is set in the center of
the hex nut that holds the bowl in place. On the
7 H.P. engine it is on top'of the carburetor.
Power adjustment screw A regulates the fuel-
to air mixture for high speed or power. If the
mixture is too rich or too lean, no engine will run
properly. An engine cannot develop all of its
power unless it is properly adjusted. Keep the
tHrottle wide open during adjustment.
Therefore, adjust A by turning it to the right,
clockwise (see Photo 7/50\ one-eighth to one-
quarter (Va to '!4) turn more for a leaner mixture
...or to the left, counter-clockwise one-eighth to
one-quarter (Va to '!4) turn for a richer mixture.
Please remember to pause for 10 to 15 seconds
after each adjustment to determine how the last
adjustment changed engine operation.
If your engine seems to have enough power
before you start tilling, and then loses power the
minute you engage the tines deeply in the soil,
it probably means that you have to open the po-
wer adjustment screw with about a '!4 to V2 turn
(counter-clockwise) .
ADJUSTING THE POWER ADJUSTMENT
SCREW
To determine the proper power adjustment
screw setting, run the engine at full power
(without choke engagement) and open the pow-
e~
adjustment screw (A in Photo 7/50 or 7/51).
counter-clockwise until you see black smoke or
notice the engine "coughing." Then, counting
the number of turns, turn the screw back to-
wards lean (clockwise) until the engine slows
down·or sputters. Then, go back counter-clock-
wise half way between the two positions. That
final position, or Y2 turn further counter-clock-
wise, should be the proper setting for tilling.
YbLJ might find in actual tilling that you still
have to open up the screw another V2 turn for
enough power. But don't run the engine so rich-
ly that it smokes-normally, you won't even see
the exhaust.
IDLE SPEED ADJUSTMENT
To increase the idling speed of the engine,
turn screw C to the right. Turn it to the leftto de-
crease idle speed (see C in Photo 7/50 or 7/51).
(Photo 7/51) 7 HP engine carburetor.
IF YOUR ENGINE WON'T START
When you can't start your engine to readjust
the carburetor, you should return the power ad-
justment screw back gently to the original set-
ting as described on page 115.
(Photo 7/52) Turn clockwise to lean fuel
mixture.