A completely blocked high speed air bleed will cause an engine to run rich under load. Is this statement true or false?

A completely blocked high-speed air bleed can indeed cause the engine to run rich under load. The high-speed air bleed is responsible for introducing additional air into the fuel mixture, particularly during higher RPMs and under load conditions. When the bleed is blocked, the amount of air available for mixing with the fuel decreases.

As a result, there is more fuel in proportion to the air being introduced into the combustion chamber, leading to a fuel-rich mixture. This rich condition can cause various issues, such as poor combustion efficiency, fouling of spark plugs, increased emissions, and potential engine performance problems. Understanding the role of the high-speed air bleed is crucial for engine tuning and performance optimization, illustrating the interdependence of fuel and air ratios in engine operation.