Tecumseh ECV100-120 - TECHNICIAN S Handbook page 14

Loosen screw until it just clears
throttle lever, then turn screw in 1
IDLE SPEED ADJUSTMENT SCREW
turn.
THROTTLE SHAFT AND LEVER
Place detent reference mark to
DETENT REFERENCE MARK
proper location.
ON THROTTLE SHUTTER
THROTTLE SHUTTER
THROTTLE SHAFT
Check spring for return action and
RETURN SPRING
binding.
IDLE PROGRESSION
Remove welch plug and blow air
HOLE
through air passages.
IDLE AIR BLEED
*IDLE MIXTURE
ADJUSTMENT
SCREW AND "O"
Remove adjustment screw. To adjust
RING (If Present)
20° slant engines, the engine must
be mounted in its normal 20° slant
*MAIN MIXTURE
position.
ADJUSTMENT
SCREW AND "O"
RING (If Present)
Check ball is not serviceable on WELCH PLUG (If Present)
some models.
*MAIN NOZZLE CHECK BALL (If Present)
*NON METALLIC ITEMS - CAN BE DAMAGED
BY HARSH CARBURETOR CLEANERS
IDLE AND INTERMEDIATE
Blow air through passage.
AIR BLEED
THROTTLE SHAFT AND LEVER
Check shaft for looseness or bind-
ing. Shutter must be positioned with
THROTTLE SHUTTER
detent reference marks on top par-
allel with shaft and to the right or 3
o'clock position. DETENT
REFERENCE MARK
THROTTLE SHAFT
Check spring for return action
and binding. RETURN SPRING
IDLE AND INTERMEDIATE
ORIFICES
IDLE AND INTERMEDIATE
Remove idle adjustment screw.
FUEL CHAMBER (COVERED
Check needle tip and condition of "O"
WITH WELCH PLUG)
ring. Remove welch plug and blow
out all passages.
IDLE AND INTERMEDIATE
FUEL MIXTURE PASSAGE
*IDLE ADJUSTMENT SCREW
AND "O" RING
ATMOSPHERIC VENT
SOFT BAFFLE PLUG
IDLE AND INTERMEDIATE
FUEL TRANSFER PASSAGE
METERING ROD OR PIN IN
FUEL TRANSFER PASSAGE
NOTE: On models which have
metering rods, do not install idle
adjustment screw with carburetors
upside down, as pin will obstruct
movement of adjustment screw
causing damage
IDLE AND INTERMEDIATE
FUEL TRANSFER PASSAGE
IDLE AND MAIN FUEL PICK UP ORFICE
*NON METALLIC ITEMS - CAN BE DAMAGED
BY HARSH CARBURETOR CLEANERS
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COMPONENTS
IDLE
(DO NOT REMOVE)
BALL PLUG
CUP PLUG
CHOKE SHAFT AND LEVER
Check shaft for binding. Position
shutter opening towards inlet fitting
CHOKE SHUTTER
side or air horn.
MAIN NOZZLE
Blow air through passage.
*INLET
Part of inlet fitting. If fuel is restricted,
FITTING
clean or replace fitting.
SCREEN
*INLET
Bulb primer models have Viton* one
FITTING
way valve, in or behind fitting.
*INLET SEAT
Remove and replace.
GASKET
*INLET NEEDLE
SEAT AND
Proper installation of assembly is im-
SPRING portant.
ASSEMBLY
Gasket and diaphragm sequence
may be reversed on some models.
*DIAPHRAGM GASKET
Head of rivet must touch inlet needle.
Rivet is hooked into inlet needle con-
*DIAPHRAGM
trol lever on some models.
Hole must be clean. On models with
ATMOSPHERIC VENT HOLE
bulb primer, vent hole is very small
and is located off center.
Loosen screw until it just clears
throttle lever, then turn screw in one
IDLE SPEED ADJUSTMENT
turn.
Removable on emission carbs. non-
MAIN NOZZLE
metallic only.
(EMULSION TUBE)
CHOKE SHAFT
Check shaft for binding position
AND LEVER
opening to bottom of air horn.
CHOKE PLATE
Blow air through passage. Do not
HIGH SPEED
remove restrictor if present.
AIR BLEED
INLET
FITTING
*INLET NEEDLE
Proper installation is important.
AND SEAT
*FLOAT BOWL
Replace.
GASKET
FLOAT
SHAFT INLET
Must hook over float tab.
NEEDLE CLIP
(If Present)
IDLE FUEL TRANSFER PASSAGE
AND ANNULAR GROOVE
Check float for leaks or dents. Clean
FLOAT
bowl and adjust float level position
gasket or gaskets.
FLOAT BOWL
If the carburetor is used on a 20° slant
*GASKET
engine, the engine must be in its
normal 20° slanted position for ad-
justment.
Check needle for damage and "O"
NUT AND MAIN ADJUSTMENT SEAT
ring for cracks. Clean all passages
*MAIN ADJUSTMENT SCREW AND
in nut with compressed air.
"O" RING SEAL
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