Harley Davidson SS/SX-1975/250 (1974 to 1976). Service manual - page 3
Again, the same symptoms that applied to checking
cutaway, above, apply here. If mixture seems too lean, pin must be moved
upward one or two grooves to allow a greater How of fuel-air mix out of
main nozzle. If mixture seems too rich, the opposite must be done. The
pin should be lowered one or two grooves.
High Speed Adjusting
In high speed operation, with throttle from about 3/4 to fully open, the
amount of fuel-air mix is governed by size of high speed jet (1), Figure
3.29, opening which supplies main nozzle (8). The opening is
non-adjustable and must be physically changed if needed. For a leaner
mixture, a smaller opening is required; for a richer mixture, a larger
opening.
REMOVING AND PARTIAL DISASSEMBLING OF CARBURETOR
Remove carburetor from motorcycle as outlined below.
Refer to Figure 3.30. Unscrew two screws (1) that
retain piston cap. This will allow piston cap (2) to be removed along
with throttle piston (3) and associated parts as an assembly.
At this time, two adjustments can be made without disassembling
carburetor further. Metering pin (4) can be repositioned from one groove
to another, and throttle piston (3) can be exchanged for one with a
different cutaway.
To change grooves of metering pin (4), remove clip (5), reposition pin,
and replace clip. To change throttle piston (3), detach control wire (6)
and metering pin (4), exchange pistons, then put control wire and
metering pin back in place.
To remove carburetor (7) from engine, loosen intake pipe clamp (8) and
pull carburetor from engine with a twisting motion.
Protect engine intake port with a clean cloth after removing carburetor.
