
Gasoline is atomized through the carburetor and mixed with air before entering the cylinder for combustion, generating power. After maintenance, the fuel-air ratio is adjusted to the optimal state. When winter temperatures are too low, this ratio is not conducive to ignition during startup, requiring an increase in the proportion of gasoline. When the weather is cold and the motorcycle is difficult to start, close the choke. Start the engine following normal procedures, and once the engine runs slightly stable, restore the choke. The vehicle can then be driven normally.

After riding for seven or eight years, I realized many people don't know how to use the choke. When starting a cold engine, pull the choke switch—this makes the carburetor supply more fuel and less air, enriching the mixture for easier ignition. After starting, don't rev the engine immediately; let it warm up for half a minute until white smoke from the exhaust reduces, then gradually push the choke back. Use the choke even in summer—a bike parked overnight outdoors still gets cold. Remember, closing the choke is more crucial than opening it. Once, I forgot to close it and rode 10 km, causing fuel consumption to spike to 6 liters and carbon buildup. Choke locations vary by model: scooters usually have it on the left handlebar, while motorcycles often place it near the carburetor—check your bike first before adjusting.

An experienced mechanic taught me three tricks: never pull the choke lever more than one-third of the way, and release it immediately when you hear the engine RPM suddenly rise; push the choke back in two stages like depressing a clutch—first return it to the half-open position, wait ten seconds, then fully close it; for old carburetor-equipped bikes, it’s best to kick the starter lever twice before pulling the choke. The worst mistake is pulling the choke while giving throttle—this can flood the engine. Once, a customer did this, and the spark plugs were drenched in gasoline. New fuel-injected bikes don’t need this, but old bikes won’t start in winter without a choke. The idea that pulling the choke before shutting off the engine makes it easier to start is a myth—it actually leads to an overly rich fuel mixture.

When I first bought my used Suzuki GN125, starting it in winter required the choke to be fully open. The specific operation was to insert the key without turning on the ignition first, pull the choke to the maximum, then turn on the ignition to start. The tachometer would surge to around 2500 RPM and stabilize. While wearing gloves, I would gently push the choke lever with my fingertips, pausing for five seconds every 10% adjustment. Once the blue smoke from the exhaust pipe turned lighter, it was ready to go, but I avoided exceeding 40 km/h for the first five minutes. The motorcycle enthusiast group often said the choke's life-saving index was even higher than hazard lights. Once after a heavy rain, my bike in the suburbs only started thanks to the choke. Note that modified exhaust pipes with poor tuning require even more choke assistance.

Three classic usage scenarios: Pull the choke fully when starting in sub-zero temperatures, then immediately push it back to 50% after ignition; Use half-choke when the air filter is damp after heavy rain; In high-altitude areas with low oxygen levels, adjust the choke accordingly. Two common mistakes beginners make: Pulling the choke while twisting the throttle causes a sudden surge in fuel intake; Keeping the choke open during long uphill climbs leads to cylinder overheating. I noticed the choke becomes more sensitive after carburetor cleaning—last week's maintenance allowed starting with just a 5mm light pull. EFI motorcycles are fully automatic, but older models like the Shineray X5 oil-cooled bikes still rely on manual operation. Remember, the choke is a temporary aid—prolonged use harms the engine.


