ching i bought a used OS max 12tz engine with a v-one rrr but on the engine i don't know the factory setting. any body know that can tell me the needle setting for OS engine. i have 3 needles and a idle screw in Carburetor 化油器.
Low Speed Needle (LSN) close it fully (with carb open, so as not to damage the main jet), teh open it until it is flush with the slide body.
Main Jet Needle or Valve (MRN) has to be flush with carburator body, and leave it there and never touch it again.
Idle Speed Needle (ISN), close it until slide valve is open about 1mm, and then when engine has started and warmed enough readjust to a slow steady idle.