Kymco Agility 50 - Service manual > Troubleshooting

Engine is hard to start

• No spark at plug
• Compression too low
• No fuel to carburetor
  • Clogged fuel filter
  • Restricted fuel line
  • Faulty float valve
  • Incorrectly adjusted float level
• Engine flooded with fuel
  • Clogged air cleaner
  • Fuel overflowing
• Intake air leak
• Contaminated fuel
• Faulty auto bystarter
• Clogged idle system or auto bystarter passages

Rich mixture

• Faulty auto bystarter
• Faulty float valve
• Clogged air jets
• Dirty air cleaner
• Flooded carburetor

Backfiring at deceleration

• Lean mixture in idle system
• Improper air cut-off valve operation

Misfiring during acceleration

• Faulty ignition system
• Lean mixture
• Faulty accelerating pump

Engine idles roughly, stalls or runs poorly

• Clogged fuel system
• Ignition malfunction
• Rich or lean mixture
• Contaminated fuel
• Intake air leak
• Incorrectly adjusted pilot screw
• Clogged idle system or auto bystarter passages
• Incorrectly adjusted float level

Lean mixture

• Clogged fuel jets
• Faulty float valve
• Float level too low
• Clogged fuel system
• Intake air leak
• Improper vacuum piston operation
• Improper throttle operation

CARBURETOR REMOVAL

Remove the frame right side cover. Disconnect the auto bystarter wire connector.

Remove the met-in box.

Loosen the drain screw and drain the fuel from the float chamber.

Disconnect the fuel tube and vacuum tube at the carburetor.

Loosen the throttle cable adjusting nut and lock nut, and disconnect the throttle cable from the carburetor.

Loosen the carburetor intake manifold band and air cleaner connecting tube band screws and then remove the carburetor.

AUTO BYSTARTER

OPERATION INSPECTION

Measure the resistance between the auto bystarter wire terminals.

Resistance: 10 max. (10 minutes minimum after stopping the engine)

If the reading is not within the limit, replace the auto bystarter with a new one.

Connect a hose to the fuel enriching circuit of the carburetor. Connect the auto bystarter yellow wire to the positive (+) terminal of a battery and green wire to the negative (-) terminal. Wait 5 minutes and blow the hose with mouth or vacuum pump. If the passage is blocked, the auto bystarter is normal.

Disconnect the auto bystarter from the battery. Wait 30 minutes and blow the hose with mouth or vacuum pump. If air can be blown into the hose, the auto bystarter is normal.

REMOVAL

Remove the set plate screws and set plate.

Remove the auto bystarter from the carburetor.

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