under the carb just ahead of the throttle plate..... 2.5 turns out from lightly seated
On the front side if the carb on the bottom
bury screw all the way in and turn out 1.5 to 2.5 turns out
If it has a carby there is a sealed mixture screw on the right side looking from the front. Drill out the the plug and the screw is behind it be careful not to damage carb
on the left side of carb. at bottom
To richen the mixture on a Yamaha SH50, you should turn the carb adjustment screw out (counterclockwise). This allows more fuel to enter the mixture, resulting in a richer fuel-to-air ratio. Conversely, turning it in (clockwise) would lean out the mixture. Always make small adjustments and test the engine's performance after each change.
turn clockwise or inward to lean the mixture.
The only setting is one screw on the top of each carb its the mixture screw and should is 1.5 turns out by default.
Only adjustment on it is the fuel mixture screw (on the bottom of carb) all the other jets are fixed, and the only way to modify is to buy new jets and install them.
There are 2 carbs so there are 2 screws. On the front carb: it is behind the throttle pulley just above the pulley. It will be behind a brass cap with a teeniny hole in it... you have to drill out the cap or put a self tapping screw in it and pull it out. (BE CAREFUL) not to drill too deep and hit the screw! On the rear carb: the screw is on the other side of the bike... right behind the throttle cable. If you are looking at the side of the bike, your screwdriver will be right against the frame. You will also have to remove the brass cap on this one.
there is two mixture screw one for air the otherone for fuel u can ajust the carb from there
Gently screw the idle mixture screw all the way in. Bring the screw back one full turn. That SHOULD make things work UNLESS the jets are gummed up.
It is a flat head brass screw on the right hand side of the carb also with a black handle is the idle screw. these are the only 2 screws apart from the big bolt on the bottom to drain the bowl