Fuel System; High Altitude Operation Service - DeWalt DW168F Manual

2. Set the piston in the top dead center position of its compression stroke.
noTE: both rocker arms ( will have the largest gap with each valve (
P7, K8)
3. Insert a feeler gauge between the rocker arm and valve to measure valve clearance.
In
ValVE
ClEaRanCE
EX 0.20~0.25
4. Adjust rocker arm pivot (R7, M8) by loosening the rocker arm locknut (S7, N8) and
adjust the pivot lock nut (R10) until the clearance is correct. When clearance is correct
tighten the rocker arm locknut.
5. Check the clearance again with nuts tightened.

Fuel System

IMpoRTanT: If the engine does not start, is hard to start or is performing poorly ensure
fuel system is clean and fuel tank contains fresh gasoline before troubleshooting.
waRnIng: Risk of explosion. Spilled gas o line and it's vapors can be come ignited from
sparks from smoking products, electrical arcing, exhaust, flame, gas es and hot engine com-
ponents such as the muffler. Make sure there are no sources of ignition, such as smoking
products near servicing location. Wipe any fuel spillage from engine.
waRnIng: Hot surfaces. Risk of burn. Engine and surrounding parts are very hot, do
not touch. Allow engine to cool prior to servicing.
DRaIn CaRBuREToR
1. Placethefuelshutoffvalve(A,ifequipped)
in the closed (horizontal) position as
shown.
2. Place an OSHA-ap proved con tain er
suitable for fuel under the carburetor
bowl. noTE: Using a funnel will allow
the fuel to flow into the container with
less spillage.
3. Remove the carburetor bowl drain bolt (
4. fuel will drain from carburetor bowl.
5. Remove the carburetor bowl and clean it in nonflammable
or high flash point solvent.
ClEanInG DEBRIs sCREEn (IF EquIppED)
1. Remove fuel cap.
2. Remove debris screen.
3. Clean debris screen. Use compressed air to blow off
debris.
U7, V7, P8, Q8)
S7, N8
R7, m8 R10
U7, V7, P8, Q8
Service
Standard
Limit
(mm)
(mm)
0.10~0.15 -
-
A
b2, K2,
f3
.
B2, K2, F3)
waRnIng: When using compressed air, user always must wear eye protection that
.
conforms to ANSI Z87.1. (CAN/CSA Z94.3).
FuEl sEDIMEnT Cup ClEanInG (IF EquIppED)
1. Place the fuel shut off valve (A, if equipped) in the closed (horizontal) position as
shown.
A
P7, K8
2. Remove the sediment cup (D) from the fuel valve on the bottom of the tank.
3. Clean the sediment cup, screen (C) and O-ring (B) in nonflammable or high flash point
solvent.
4. Drain and remove gas tank, flush until clean.
5. Replace or clean fuel filter. Fuel filter may be inside gas tank where fuel exits or an
in line fuel filter may be on the fuel line. See service Bulletin (SB06109)
REassEMBlE
1. Reinstall O-ring, sediment cup, carburetor bowl, carburetor bowl drain bolt, debris
screen and fuel cap
2. Replace inline filter (if equipped).
3. Turn the fuel shut-off valve (A, if equipped) to the open (vertical) position and check for
fuel leaks.

High Altitude operation Service

High Altitude modification should only be made to engines operating at above
5,000 ft. (1524 m) for an extended period as manufactured engines are suitable for opera-
tion up to 5,000 ft. (1524 m) above sea level. noTE: Reset to factory setting immediately
when engine is moved to operate below 5,000 ft. (1524 m). To reset, replace high altitude
main jet with low altitude main jet. If the engine is used at low altitudes after a carburetor
modification, the carburetor may cause the engine to overheat and result in serious engine
damage.
1. Set the fuel valve in the off position. Remove the carburetor drain bolt (
the carburetor bowl (
E3, J2)
2. Remove the fuel cutoff solenoid (
Phillips screwdriver.
E3, J2
b2,
K2, f3
3. Remove the carburetor bowl (
16
A
b
C
D
and allow fuel to drain into a suitable container.
from the carburetor bowl using a
D3, if equipped)
V3, L2
D3
and retaining bolt (V3, L2) with a 14 mm socket.
E3, J2)
A
from
B2, K2, F3)
X2
I4