Component Effect Vs. Throttle Opening; Mikuni Vm Fuel Delivery Chart - Polaris Magnum 2x4 Service Manual

FUEL SYSTEM/CARBURETION
Component Effect vs. Throttle Opening
The throttle opening chart below demonstrates component relationship to fuel flow versus throttle valve opening.
The pilot system's main function is that of a low speed jet. Its most effective range of fuel delivery is from idle
to approximately 3/8 throttle valve opening.
The throttle valve controls the rate of engine air by its movement up and down in the carburetor venturi. At small
throttle openings the air flow is regulated chiefly by the valve cutaway, with greatest effectiveness at 1/4 throttle
opening. Throttle valves are numbered 1.0, 1.5,2.0, etc., according to the size of the cutaway. Decreasing the
cutaway number will increase the amount of fuel delivered in its effective range.
The jet needle and needle jet have an effective operating range from approximately 1/8 to 7/8 throttle opening.
The amount of fuel delivered during this range relies upon the jet needle clip position, as well as the needle jet
size and other specifications.
The main jet affects fuel delivery at 1/4 throttle and consistently increases to full throttle opening.
Mikuni VM Fuel Delivery
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EFFECT
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Polaris Industries Inc.
1/4 3/8 1/2 5/8 3/4
THROTTLE OPENING
4.21
7/8
FULL
Throttle Valve Cut-Away
Jet Needle/Needle Jet
10/96