Carb soleniod

[2ndscooter]

 :)Just bought  a 2004 Shanghai Jailing 50 cc  4 stroke. Have a question a bout the carb  en richer.  Looking at the wire diagram on the in line service manuals . It looks like the solenoid is powered by the dynamo  and the needle will not move until engine is running. Does the system richen the mixture when cold or under power. I assume that it is in place of a choke. not a power enrichment device.

[Fox]

There is a third circuit in the carburetor that allows extra fuel into the engine when cold through an enrichment jet. The auto enricher unit gets warm, the needle extends outward and shuts off the enrichment circuit after a minute or so effectively leaning out the mixture.

So when the engine is turned off the enricher moves back to "rich" position.

[2ndscooter]

 How is the solenoid powered from  B+ or direct from the alternator.I see a resistor pack that I assume changes the resistance to ground according to ambient  temp.

[Fox]

Honestly I'm not that great at electrical but since it is only powered when the engine is running I assume it comes straight from the stator.  Below is a generic Chinese scooter wiring diagram. At the top right corner it looks like a yellow and it comes straight from the stator so it's probably AC voltage.




There's a couple of maint. manual .pdf files at the link below. The GY6 and the 50-150cc manuals are good. The Arrow is for 150cc but is also good to have around.
http://www.chinesescooterreference.com/manuals.htm