Trying to find out what part this is what it does if it can be fixed and if not what needs to be replaced its a 125cc 4stroke pit bike

SOURCE: Battery on 125cc Suzuki GS is ok- but not being charged

You need to have stator coil tested.
An alternate problem could be the regulator/rectifier.
Both of these should tbe checked by a dealer

Cheers

Jon

SOURCE: piston rings

First, be sure they actually do fit the bore. Take a ring and insert it in the bore. push the ring halfway into the bore using the piston. There should be about a 1/32" gap in the ring. Anything more than 1/16" and you need rings the next size up. If the ring won't go into the cylinder because the gap fully closes, the rings need to be a smaller size.

With the correct size rings, put them on the piston. Some pistons have an index pin in the ring groove Fit the gap to the pin. Put the piston mid-stroke and place the cylinder over the top of the piston. Squeeze the rings closed as you gently tap the cylinder downward and over the rings.

Please rate this solution. Thanks garethholleb!

SOURCE: how to set timing on 125cc thumper pit bike i.e

there should be a inspection plug at the top of the stator cover if you remove this and turn the crank over you will see a line that is TDC or put a screw driver down the plug hole and turn the crank untill the piston is at TDC eg screw is pushed up to the max , then turn a bit more and it will go down when its at the top of the movement this is TDC Top Dead Center. in the cam cover there is a dot on the outer edge of the sprocket this aligns with a notch or flat mark on the very top of the inside of the engine. Dont turn cam while piston is TDC or you can bend valves, set cam 1st. then piston then fit the chain.