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TUNING

Idle Speed Screw

Hex/Slotted screw located on driver's side, controls idle speed when choke is fully open and engine is at operating temperature. Turning clockwise will increase idle speed, counterclockwise will decrease idle speed.

 

Idle Mixture Screws

Slotted screws located on the underside of the carb on either side of the power valve housing, facing forward. Controls air/fuel mixture of idle circuit(<800 RPM). Turning clockwise will lean the fuel mixture, counterclockwise will richen the idle mixture. A good setting to start with is 2 turns out from lightly seated.

Note 1: Both screws must be turned equal amounts when adjusting.

Note 2:Does not affect air/fuel ratio of main circuit(i.e.:Jets)

 

Fast Idle Screw

Slotted screw located on passenger's side, on fast idle lever. Controls idle speed at colder engine temperatures when choke is closed and/or partially open via the fast idle cam. Turning clockwise will increase fast idle speed, counterclockwise will decrease fast idle speed.

 

Float Level

Brass or Nitrophyl float, located in the float bowl. Can be set dry or wet (wet is most accurate). Settings vary depending on application, must be set to factory specifications.

 

Choke Cap (Automatic Choke Models)

Black phenolic plastic cap, located on passenger's side. Controls the rate at which the choke plate opens in response to engine temperature. Turning clockwise will open choke faster, counterclockwise will open choke slower.

 

Choke Swivel/Lever Screw

1/4 drive hex screw on passenger's side, on Choke Swivel/Lever. Adjusts Fast Idle Cam linkage.

 

Accelerator Pump Settings

Settings vary by application, set to factory specifications.