M/C Carburetors-?

Question

Is it true that a CV carb slide works off barometric pressure and intake suction as the butter fly valve is opened up? 2.Is it true that a slide carb. has no butterfly and is controled by the throttle cable only? 3. Do slide carbs.allow faster throttle responce?

Answer 1

All of your assumptions are correct.
--Slide carbs - when the slide is lifted by the throttle cable, more fuel is sucked into the mixture before entering the engine. A larger explosion in the combustion chamber, because of the volatility of the fuel/air mixture causes the piston to move on it's down stroke faster, creating a stronger vacuum. This in turn pulls more air through the venturi of the carb and pulls more fuel into the mixture at a faster rate.
--CV carbs - are just that, a constant velocity. When the butterfly valve is opened, the engine pulls more air through the venturi of the carb. The small amount of vacuum increase (because of the lesser amount of fuel in the mixture - lower volatility) lifts the slide at a constant slower rate (than a slide permitting fuel NOW) allowing more fuel into the mixture.
--CV - open butterfly - creates a stronger vacuum - lifting slide - allowing more fuel.
--Slide - lift slide - more fuel into the mixture - higher volatility in combustion chamber - creates a stronger vacuum - sucks in more fuel.

Answer 2

1. Yes
2. Yes
3. Depends on the application and other factors