7 Carburetion Air-fuel Requirements Ratio of air to fuel.Stoichiometric ratio of 14.7:1Example 14.7 lbs of air to 1 lb of fuelFuel ratiosRich / lean
8 Carburetor Operating Conditions ColdChoke / primeLow speedIdleMid speedIdle and high speedAccelerationAccelerator pumpHigh speedMain discharge nozzle
9 Carburetion Pressure Differences VacuumPressure less than atmospheric pressureAtmospheric pressureForce of air on a surface at 14.7:1psiVenturi principleA restriction in an air passage which causes an increase in air speed and a decrease in air pressure
10 Carburetion Pressure Differences Air hornAir enters at Atmospheric pressureVenturiHigh vacuum is createdEngine sideLow vacuum created on the intake stroke
11 Carburetion Atomization Vaporization Turning a liquid into little dropletsVaporizationTurning liquid droplets into a vapor or gaseous state
12 CarburetionTypes of carburetors - air directionSide draft
13 CarburetionTypes of carburetors - air directionUp Draft
14 CarburetionTypes of carburetors - air directionDown draft
32 Running Conditions Too Rich Too Lean Just Right Air-fuel mixture with excessive fuelHC and CO pollutionExhaust black sootToo LeanAir-fuel mixture lacking fuelCO and NOX pollutionEngine overheatingJust RightSmooth engine operationRapid AccelerationLow pollution / Clean ExhaustNormal operating temperature
33 CarburetionThe purpose of the fuel system is store, deliver, mix and meter air and fuel for the engine to function over a variety of operating conditions.
Your consent to our cookies if you continue to use this website.