How does a constant velocity carburetor work?
Constant vacuum carburetors, also called variable choke carburetors and constant velocity carburetors, are carburetors where the throttle cable was connected directly to the throttle cable plate. Pulling the cord caused raw gasoline to enter the carburetor, creating a large emission of hydrocarbons.
Where is the idle screw on a carburetor?
The idle mixture screw controls the air fuel mixture at idle speed, and often is located near the throttle plate.
What is the screw on the bottom of the carburetor?
If it is the screw in front and underneath the carb throat that bolts to the intake manifold, it is a fuel screw. When you turn the screw out, it richens the mixture. When you turn it in, it leans the mixture.
Why does my 2 stroke engine only run on choke?
When you turn the choke on for a carburetor, it is creating a rich condition. So, when your bike only runs on choke, it is because the “rich” mixture that is being burned is actually closer to the appropriate mixture. Then, when you turn the choke off, it becomes much too lean and will not run.
How do I adjust my idle RPM?
Turn the idle screw, now exposed from the protective rubber coating, in order to adjust the idle. Loosen the screw in a counter-clockwise fashion to increase idle speed or tighten it in a clockwise manner in order to decrease the idle speed. Ideally, you will want the idle to rest at 650 RPM.