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CARBURETOR VISUAL IDENTIFICATION
Series1 Carburetors
Series 1 carburetors are used on some 4 - 7 model
overhead valve engines. This float style carburetor
has a smaller venturi than the Series 3 or 4 carburetor
and has no bosses on each side of the idle mixture
screw. The main and idle mixture may be fixed or
adjustable. A remote primer or choke may also be
used with this carburetor (diag. 8).
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Series 3 & Series 4 Carburetors
Series 3 or 4 carburetors are generally used on 8
through 14 model 4-cycle engines. The quickest way
to identify these carburetors is by the presence of
bosses on each side of the idle mixture screw (diag.
9).
To determine whether the carburetor is a Series 3 or
Series 4, look at the throttle end of the carburetor.
Series 3 will have one throttle plate screw (diag. 10).
The Series 4 will have two throttle plate screws (diag.
11).
Series 7
Series 7 carburetors are totally nonadjustable. The
die cast carburetor body is similar in appearance
and slightly longer than the Walbro LMK body. The
choke shaft is made of a plastic material with an
internal slot to hold the choke shutter. The carburetor
base is flat to accept a Vector style bowl that is held
on with a wire bail. (diag. 13)
9
11
10
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Series 6 Carburetors
Series 6 carburetors are used on 2 and 4-cycle
engines in the 3 to 6 model range. Series 6 uses a
simple fixed idle and fixed main fuel circuit. Series 6
carburetors are commonly used on rotary mower
applications. Series 6 are nonadjustable, with a
stepped primer bulb and a bowl prime system (diag.
12).
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