What are the reasons for a motorcycle not accelerating?

[SanMaggie]

Here are the reasons why a motorcycle may not accelerate: 1. Carburetor blockage: If the idle jet is clogged, it will manifest as no idle speed; if the main jet is clogged, it will show as poor high-speed acceleration, i.e., the motorcycle won't accelerate. In this case, removing and cleaning the carburetor can restore normal function. 2. Improper air-fuel mixture: When the mixture is incorrect, the bike will have unstable idle speed and poor acceleration. Simply adjust the idle screw until the idle stabilizes. 3. Valve clearance too small: The standard valve clearance for ordinary motorcycles is between 0.05-0.12mm. To check the valve clearance, you can remove the valve cover or cylinder head cover, align the valve timing, and inspect the valve clearance. Alternatively, if you move the rocker arm by hand and feel it is very tight with no gap, the clearance is too small.