Engine 125 cc
Honda CB Shine
I have Honda shine. When I start my bike it gets auto accelerated and shows RPM is 4.
When I ride my bike for long time it gets auto accelerated more.
Assuming what you are saying is that your engine goes to 4,000 RPM as soon as you start the engine, and increases as you ride...This sounds like your throttle is stuck, or is sticking.
NOTE: It is dangerous to ride a motorcycle in this condition. For your safety, it would be a good idea to refrain from doing so until it is fixed.
The most common issue with motorcycles in these cases is damaged cables from being dropped, crashed or corrosion from being left out in the weather. Kinks or crush damage can cause it to be difficult for the cable to slide back and forth in the housing, thereby keeping the throttle open.Check the cables from the handlebars to the carburetor for any damage. Replace any damage you find.
If there is no evidence of physical damage, check for debris in the fuel system. Dirty fuel can cause passages in the carburetor to be obstructed and/or become sticky, in turn causing the throttle to stick open. A good fuel system treatment can help, but at this point, you may need to have it serviced.
There is a small screw in the carburetor which sets the idle speed of your bike which sets rpm for the idle state, This can be manually adjusted, tune the screw as recommended in the user manual or tell a mechanic to adjust the slow speed. This will solve the problem, if it still gets accelerated. Check the accelerator cables and replace if necessary.
Don't ride it this condition for long. It will decrease the fuel efficiency and can cause other issues to the engine and carburettor.
I don't know about Honda shine but my pulsar 220 has a throttle or rpm adjuster or whatever u call it which lets u set the initial rpm when u start the bike and also prevents it from turning off quickly.burns petrol but is better than using the self repeatedly.it also helps in winters.i had set it according to my need..If it is the same case it must have happened by mistake.in my bike it is located near the carbonator.consult ur mechanic,it might be a matter of few seconds And it also might be due to the throttle on ur handlebar being jammed.get it oiled and see