D14/4
CARBURETTER
C4
Having dismantled the carburetter, carefully clean
all parts in petrol (gasoline). Hard deposits on the
carburetter body are best removed with a light-grade
wire brush. After washing the parts in clean petrol,
allow to dry and ensure that all holes or small drillings
are free from dirt. A hand pump is ideal for "blowing
through" and blockages in the drillings. Inspect the
component parts for wear and check that the jets are in
accordance with the recommended sizes in General
Data.
Reassembly is simply a reversal of the above
instructions but remember to replace any gaskets or
"O"-rings that appear unserviceable. Refer to fig. C1
for guidance.
INSPECTING THE CARBURETTER
COMPONENTS
The parts most liable to show wear after considerable
mileage are the throttle valve slide and the mixing
chamber.
(1) Inspect the throttle valve for excessive scoring of
the front area and check the extent of wear on the
rear slide face. If wear is apparent, the slide
should be renewed; be sure to fit valve with
correct degree of cut-away (see General Data).
(2) See that the air slide has not been subjected to
excessive wear and that it is a good fit in the jet
block. Ensure also that the valve return spring is
serviceable.
(3) Check the throttle return spring for efficiency.
Check also that it has not lost its compressive
strength by measuring the free length and
comparing it with the figure given on page GD3.
(4) Examine the needle jet for wear or possible
scoring and check the tapered end of the needle
for similar signs.
(5) Check the float needle for efficiency by inserting
it into the float needle seating block, pouring a
small amount of petrol (gasoline) into the aperture
surrounding the needle and checking it for
leakage.
(6) Ensure that the float is not punctured by shaking
it to see if it contains any fuel. Do not attempt to
repair a damaged float. A new one can be
purchased at a small cost.
(7) Check the fuel filter that fits over the needle
seating block, for any possible damage to the
mesh. If the filter has parted from its supporting
structure it will allow the petroil mixture to pass
through unfiltered.
HINTS AND TIPS
Throttle Cable
See that there is a minimum of backlash when the
twist grip is turned back and that any movement of the
handlebar does not cause the throttle to open.
Use the adjuster on the cable to obtain the correct
setting and ensure that the throttle valve shuts down
freely.
Fuel Feed
Unscrew the float chamber "banjo" bolt, remove the
"banjo" and take off the filter gauze from the needle
seating.
Ensure that the filter gauze is undamaged and free
from all foreign matter. To check fuel flow before
replacing the "banjo", turn on fuel tap momentarily
and see that the fuel gushes out.
Flooding
This may be due to a worn needle or a punctured float,
but is more likely due to impurities (grit, fluff etc.) in
the tank. This trouble can sometimes be cleared by
periodically cleaning out the float chamber. If,
however the trouble persists, the fuel tank must be
drained and swilled out.
Carburetter Air Leaks
Erratic slow-running is often caused by air leaks
between the joints at the carburetter flange and the
cylinder and can be detected by applying oil around
the joints.
Summary of Contents for D14/4 BANTAM SUPREME D14/4 BANTAM SPORTS
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Page 28: ...D14 4 ENGINE B2 FIG B1 Engine exploded ...
Page 47: ...D14 4 CARBURETTER C2 FIG C 1 Concentric carburetter exploded ...
Page 55: ...D14 4 FRAME AND FITTINGS D2 FIG D1 Frame dimensions ...
Page 100: ...D14 4 ELECTRICAL SYSTEM G14 FIG G8 Wiring diagram all models except Bushman Pastoral ...
Page 101: ...D14 4 ELECTRICAL SYSTEM G15 FIG G9 Wiring diagram Bushman Pastoral models ...