Final Adjustments (Non-Emission Engines); Non-Adjustable Carburetor - Tecumseh ECV105 Technician's Handbook

PRE-SETS AND ADJUSTMENTS
(TECUMSEH AND WALBRO
CARBURETORS)
NOTE: OVERTIGHTENING WILL DAMAGE THE TAPER
PORTION OF THE NEEDLE. All adjustments should be
made with the carburetor in the operating position.
Turn both the main and idle mixture adjusting screws in
(clockwise) until finger tight.
Now back the mixture screws out (counterclockwise) to
obtain the pre-set figure in the chart shown at right.
FINAL ADJUSTMENTS (NON EMISSION ENGINES)
Start the engine and allow it to warm up to normal operating temperature (3 - 5 minutes). Set the speed control to the
HIGH or FAST position. From the recommended preset position, turn the main mixture adjustment screw in (clockwise)
slowly until the engine begins to run erratic (lean). Note the position of the screw. Now, turn the screw out (counterclockwise)
until the engine begins to run erratic (rich). Turn the screw in (clockwise) midway between these two positions. This will
be the best setting. (diag. 21, 22 & 23).
Set the speed control to the IDLE or SLOW position. Adjust the idle mixture screw following the same procedure used to
adjust the main mixture adjustment screw.
IDLE MIXTURE
SCREW
If further adjustment is required, the main adjustment should be made under a loaded condition.
If the engine stops or hesitates while engaging the load (lean), turn the main mixture adjusting screw out
(counterclockwise) 1/8 turn at a time, testing each setting with the equipment under load, until this condition is corrected.
If the engine smokes excessively (rich), turn the main adjusting screw in (clockwise) 1/8 turn at a time, testing each
setting with the equipment under load, until this condition is corrected.
After the main mixture screw is set, move the speed control to the IDLE or SLOW position. If the engine does not idle
smoothly, turn the idle mixture screw 1/8 turn either in (clockwise) or out (counterclockwise) until engine idles smoothly.
Recheck the high and low R.P.M. setting and adjust as necessary.
DUAL SYSTEM AND SERIES 6
NON-ADJUSTABLE
PRIMER NO CHOKE
16
TECUMSEH CARBURETORS
SERIES 1
MAIN MIXTURE
IDLE MIXTURE
SCREW
SCREW
21
NON-ADJUSTABLE CARBURETORS
SERIES 8
CAPPED FIXED
JET
24
Tecumseh Carburetors
Engine Model
All models with float-type
carburetors
All models with diaphragm-type
carburetors
Walbro Carburetors
Carburetor Model Number
LMH
WHG & LME
LMK
SERIES 3 & 4
IDLE MIXTURE
MAIN MIXTURE
SCREW
22
SERIES 9
MIXING WELL
CAST BUT
NOT
MACHINED
IDLE JET
25 CAST BUT NOT MACHINED
Main Pre-set
Idle Pre-set
1-1/2 turn 1 turn
1 turn 1 turn
1-1/2 turn
1-1/2 turn
1-1/4 turn
1-1/4 turn
Fixed 1 turn
DIAPHRAGM
SCREW
MAIN MIXTURE
SCREW
SERIES 10
CAPPED IDLE
26 RESTRICTOR
23
CHOKE
27