Throttle.

5.2.2.4.5

Throttle.

New style throttles are removed by using a Phillips screw driver to re-

move the throttle valve screw. After removal of the valve, the throttle

may be lifted out. Reverse procedure to install.

5.2.2.4.6

Fuel Pipe.

Check balls are not used in these fuel pipes, The screen housing or pipe

must be replaced if the screen cannot be satisfactorily cleaned. The long

pipe supplies fuel from the tank to the pump. The short pipe supplies fuel

from the tank cup to the carburetor. Fuel pipes are nylon or brass. Nylon

pipes are removed and replaced by using a socket, or open end wrench.

Where brass pipes are used, the screen housing only is replaced. Clamp

the fuel pipe in a vise (Do not over-tighten). Drive off the housing with a

screw driver. The new housing is installed by tapping it on the pipe with

a soft hammer.

5.2.2.4.7

Needle Valve and Seat.

Remove needle valve to inspect. If carburetor is gummy or dirty, remove

seat to allow better cleaning of metering holes.

5.2.2.4.8 Pump Disassembly and Repair.

Remove fuel pump cover, diaphragm, spring and cup. Inspect diaphragm

for punctures, cracks, and fatigue. Replace if damaged. On early models,

the spring cap is solid. On later models, the cap has a hole in it. New

style supersedes the old style. When installing the pump cover, tighten

the screws evenly to insure a good seal.

5.2.2.4.9

Carburetor Adjustment.

The initial setting of the needle valve is made by turning the needle valve all

the way in, then turning out 1-1/2 turns. Final adjustment is made with the

engine running. With the engine running at approximately 3000 RPM, turn

the needle valve in until the engine starts to lose speed (lean mixture) then

slowly open needle valve past the point of smoothest operation, until engine

just begins to run unevenly. This mixture will give best performance under

load.

Hold throttle in idle position. Turn idle speed adjusting screw until 1750

RPM idle speed is obtained. If engine tends to stall or die out under load,

open needle valve slightly. This richer mixture may cause a slight uneven-

ess in idling.