Thermostatic valve not operating at high ambient temperature (this prevents cool air from flowing through main body and flange into intake manifold to cool fuel-air mixture and inhibit fuel evaporation)
As the valve opens, it allows outside air to flow directly into the intake manifold, leaning out the rich air fuel mixture. Valve starts to open when engine compartment temperature reaches 140 F, or 60 C and fully opens at 167 F, 75C.
The primary cause is excess heat, often due to inadequate insulation or a hot engine. Think of it as a car having a fever, with the carburetor acting as the thermometer.
Carburetor percolation can manifest as hard starting, rough idling, and even flooding. It's like your car is telling you, "Hey, I'm not feeling well. Something's wrong."
Percolation can result in stalling, engine hesitation, and overall poor performance. Imagine running a marathon while having the flu; it's essentially the same scenario for your engine.
Uncontrolled percolation can cause fuel wastage and poor fuel economy, akin to a tap leaking precious water drop by drop.
As with our health, prevention is better than cure. Regular check-ups, clean-ups, and replacements of old parts can ensure your carburetor stays in top form.