TGB Blade 250 ATV Quad Service Repair Manual, Page 20Get this manual
1GENERAL INFORMATION CEngine runs sluggish (especially in low speed and
Probable causes
Check ignition timing (using ignition lamp)
Abnormal
Incorrect ignition timing (malfunction of CDI or AC alternator)
Adjust the air screw of carburetor Good Poor
Air sucked through carburetor gasket No air sucked Remove spark plug, install spark plug into spark plug cap and perform spark test against engine ground
Rich mixture (loosen the screw) Lean mixture (tighten the screw)
Poor heat insulation gasket Carburetor lock loose Poor intake gasket Poor carburetor O-ring Vacuum hose crack