Carburetor Rejetting in 70cc bikes

Disclaimer: I am sharing this to let you guys know that we can increase the mileage by some alterations. So, i should not be blamed if any thing goes wrong with your bike. And it will be better if you ask a mechanic to help you out with the rejetting purpose. Plus if you got any additional information kindly share it with me.

Recently, I bought a used bike less then an year old, but its average was less than 30km/ltr. So i took it to a mechanic who tuned the bike and rejetted the carburetor. The bike started to give 40-45km/ltr. But that was not so much economical for me. So i started to do some research and found out. Fuel and Idle speed screws on right side of the carburetor of bike.
 The screws are 1 1/2 turns by factory settings.
Fuel Screw:
Fuel screw has two functions making the fuel lean or rich.

Turning it anti clockwise that is left side, will make the fuel richer. That means less fuel will be used but will leave a black spot if turned more than needed.
In the clockwise direction the mixture gets leaner. Means engine will gets hotter soon.

In some of the posts on some forums (whose address i forgot) i found that we can turn the screws to 3 turns on left side with out doing any major damage to the engine.
So i did the same. I set the fuel screw on 3 turns from full tight, and same for the idle switch.
My bike gave 50km/ltr average on my last ride.

Do the settings, after running the bike for atleast 15 mins. Set the fuel switch and then turn the idle switch later on the settings of fuel switch to get 900RPM on idle speed,(i dont have a RPM meter, i just did it based on my hearing power).
Try to run bike between 40 to 60kmh.
When ever you can use, use 4th gear.
If you have a question, put it in the comment.

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