Van's Aircraft RV-12 Maintenance Manual

Rev.5
12-13
●
NOTE:
W
HEN CHECKING THE IDLE SPEED DURING THE ADJUSTMENT PROCEDURE
ONLY PULL LIGHTLY ON THE THROTTLE CONTROL UNTIL YOU JUST FEEL THE IDLE
STOPS ON THE CARBURETORS
. A HEAVY PULL ON THE THROTTLE CONTROL WILL
FLEX THE THROTTLE ARMS AND GIVE AN INACCURATE IDLE SPEED.
●
NOTE:
I
F THE THROTTLE HANDLE IS HELD FULLY AT IDLE FOR AN EXTENDED
PERIOD THE IDLE MAY CREEP DOWN TO APPROXIMATELY
1550 RPM. THIS IS
PERMISSIBLE WHEN SETTING UP THE CARBURETORS BUT DURING NORMAL GROUND
OPERATIONS THE IDLE SPEED SHOULD BE KEPT AT OR ABOVE
1650 RPM, OR
WHATEVER IDLE SPEED IS REQUIRED TO ALLOW THE ENGINE TO RUN SMOOTHLY
.
OPERATING AT IDLE SPEEDS WHERE THE ENGINE IS MAKING A KNOCKING/RATTLE
TYPE NOISE WILL CAUSE GEARBOX DAMAGE.
●
NOTE:
O
FTEN TIMES WARMING THE ENGINE BY RUNNING IT ON THE GROUND DOES
NOT QUITE BRING IT UP TO NORMAL OPERATING TEMPERATURES
. THIS WILL HAVE A
SLIGHT EFFECT ON WHAT THE ACTUAL IDLE
RPM WILL BE ONCE THE AIRPLANE HAS
BEEN FLOWN FOR A FEW MINUTES
(FULLY WARMED UP). THE DIFFERENCE TENDS TO
BE A
50 – 75 RPM INCREASE. FOR THIS REASON, UNLESS YOU ARE DOING THE
CARBURETOR SYNCHRONIZATION PROCEDURE IMMEDIATELY AFTER FLYING THE
AIRPLANE
, ADJUSTING FOR AN IDLE SPEED NEAR THE BOTTOM OF THE RECOMMENDED
RANGE WILL NET YOU A PROPER IDLE OF ABOUT
1650 RPM AFTER THE ENGINE IS
FULLY WARMED.
●
NOTE:
V
ERIFY THE IDLE SPEED AND ADJUST AS NECESSARY TO ACHIEVE
1600-
1650 RPM AND SMOOTH ENGINE OPERATION (REMEMBER TO ONLY PULL LIGHTLY
AGAINST THE CARBURETORS IDLE STOPS).
19. A final idle speed adjustment may be required by resetting the idle speed
adjustment screws, accordingly. Turning the idle speed adjustment screw
clockwise will increase the engine speed / counter clockwise will decrease it.
Equal adjustments must be made to each carburetor. Any major adjustments
require verification of all parameters in this procedure. Before moving on to the
next step, verify that the vacuum gauge readings for the two carburetors are
balanced at idle and at off idle throttle settings.
20. Use light pressure on the throttle control to hold it at the idle position, then tighten

Van's Aircraft RV-12 Specifications

General

Brand	Van's Aircraft
Model	RV-12
Category	Aircrafts
Language	English