Initially, there would only 2 possible reason for a 50cc scooter to cut out/stall: fuel and ignition/spark. Based on that, you may want to check:
if it is a two-stroke engine, the 2T oil pump or if you are using pre-mix, the ratio as specified by the manufacturer. Post back make & model;
ignition system which includes the CDI, the trigger/pulse inside the magneto, the coil, sparkplug wire and the sparkplug itself. In some models, there is an engine kill switch which is but a wire that ground the CDI to turn it off (most likely culprit). This is similar to the operation of the ignition switch;
In some models (specially 4 stroke), the CDI operates with power from the battery and not from the magneto alone. These models require a consistent 12VDC. If the regulator is defective and the voltage fluctuates or goes up incontrolled (when revved), the CDI tends to shutdown;
This of course assuming engine is stock with no modification to the piston, cylinder head (compression ratio) nor the jettings of the carb.
Check and perform preliminary visual or necessary inspection. Pls post back result(s). Good luck and Thank you for using FixYa.
Answers & Comments
Hi and welcome to FixYa,
Initially, there would only 2 possible reason for a 50cc scooter to cut out/stall: fuel and ignition/spark. Based on that, you may want to check:
- if it is a two-stroke engine, the 2T oil pump or if you are using pre-mix, the ratio as specified by the manufacturer. Post back make & model;
- ignition system which includes the CDI, the trigger/pulse inside the magneto, the coil, sparkplug wire and the sparkplug itself. In some models, there is an engine kill switch which is but a wire that ground the CDI to turn it off (most likely culprit). This is similar to the operation of the ignition switch;
- In some models (specially 4 stroke), the CDI operates with power from the battery and not from the magneto alone. These models require a consistent 12VDC. If the regulator is defective and the voltage fluctuates or goes up incontrolled (when revved), the CDI tends to shutdown;
This of course assuming engine is stock with no modification to the piston, cylinder head (compression ratio) nor the jettings of the carb.Check and perform preliminary visual or necessary inspection. Pls post back result(s). Good luck and Thank you for using FixYa.
Check that fuel is getting to carb, and check carb settings.
There is a fuel filter on many scooters, that is on fuel lines between pump and carb, bypass it to test and eventually replace it.
Test fuel pump.
If fuel is ok, check spark plug.
When does it quit... idling... during operation ?