Chain Adjustment Slipper; Checking Condition Of Primary Chain; Carburetor Adjustments; Carburetor Jetting - Royal Enfield Bullet RES 500 Service Manual

CHAPTER 4
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BASIC DAY-TO-DAY MAINTENANCE: CHECKING A N D ADJUSTMENTS
Chain Adjustment Slipper
The chain adjuster is of the "slipper" type, on the
bottom run of the chain. Loosen off the locknut,
and adjust the setting bolt accordingly, tightening
the locknut when finished. Check the chain in a
number of places before reassembling the chaincase,
and replacing the various outside accoutrements.
Then replace the primary case oil
-
SAE 20W is
recommended by the factory, but type F Automatic
Transmission Fluid is also very popular, formulated as
it is for specifically this kind of application
-
clutches
and chains, lubrication without destroying friction
-
I have used it in all my primary cases since the late
'601s, and found
it
t o be excellent in terms of clutch
operation and chain lubrication.
Checking Condition of Primary Chain
Unless the machine has a great many miles on
it,
o r has been run without chaincase oil for some time,
it
is very
unlikely that the primary chain will need replacement. The indication will be that there is no longer any adjustment
possible, ie it is too slack and can't be tightened enough. In this case, refer t o the "heavy mechanicals" section for
instructions on removing and replacing.
CARBURETOR ADJUSTMENTS
Carburetor Jetting
Improperly set carburetion can cause wooly or sputtery running at road speeds, spit-back from the carburetor,
and hard starting. Most importantly, an improperly lean mixture can cause detonation, which will make short
work of a piston. Consequently, a regular check of carburetion and timing is very important in a high-perform-
ance air- cooled engine, such as that of the Bullet.
The Carburetor Circuits
Discussion of carburetor operation is usually done in terms of the "circuits"
-
the flow paths for the fuel.
The Float Circuit
The gasoline is mixed with the airflow through the carburetor by being drawn by Bernoulli effect through one o r
another of the jet circuits. A constant level of fuel is maintained in the carburetor, t o supply the various circuits, in
the float bowl. The level in this reservoir is maintained by the float valve
-
a needle valve which is normally open,
but which is closed by a lever attached t o a float, which is raised by fuel level in the float bowl. Thus the level in
the bowl is regulated as it flows in through the float valve, and out through one or another of the jet circuits.
The Jet Circuits
m
The Enrichening Circuit
-
allows extra-rich mixture to be drawn into the engine for cold starting purposes.
Controlled by the Enrichening Lever, often misnamed the choke.
The Enfield BULLET MANUAL by Pete Snidal O
2002 33