Bike is back firing and bogging down when I get on the throttle. Need to know how to adjust carb.

There could be several possible causes for your 2002 Hyosung GV250 bogging down when starting out. Here are a few things to check:

1. Fuel system: Ensure that the fuel system is functioning properly. Check for clogged fuel lines, dirty fuel filter, or inadequate fuel supply.
2. Carburetor: The carburetor may be dirty or clogged, causing a lean fuel mixture. Clean the carburetor or have it professionally cleaned if needed.
3. Air filter: A dirty or clogged air filter can restrict airflow to the engine, leading to poor performance. Check and clean or replace the air filter as necessary.
4. Spark plugs: Worn or fouled spark plugs can cause poor ignition, resulting in engine bogging. Check and replace the spark plugs if necessary.
5. Exhaust system: A partially blocked or restrictive exhaust system can cause poor performance. Check for any obstructions and clear them if necessary.
6. Electrical system: Ensure that the battery and charging system are functioning properly. Weak battery or faulty charging system can lead to inconsistent power delivery.

If these steps do not resolve the issue, it may be necessary to have a professional mechanic inspect the motorcycle to diagnose the exact cause of the problem.

You need to take this bike to professional mechanic and have THEM clean and set the carbs,,, and put a NEW air filter in and NEW SPARK PLUGS.... it will be fine!!

REPLACE the BATTERY IMMEDIATELY !!!..So, you put in new spark plugs.. not better..?? .. take it to a QUALIFIED PROFESSIONAL (very experienced and factory trained) to have the carbs checked,,!!.. "rebuild kits" are usually a disaster. they ask you to replace parts that don't need replacing with generic junk... I get so tired of idiots that think they know something about a carburetor.. and then attempt to install a generic "rebuild kit" .....and ......99% of the time, a SIMPLE CLEANING and SETTING/SYNCHRONIZATION is ALL THEY NEED!!!

There is an adjustment screw under the carb on the left hand side

you need to clean out the carburetor, the gas isn't getting through it. the bogging is caused by all the gas going into the engine cause of the choke, it dumps raw fuel into the engine and cant burn it all, there fore bogging and acting sluggish, the back firing is caused by the same thing, too much fuel going into the engine and being deposited in the pipe and igniting occasionally, clean the carb out and it will run fine

Sounds like a lean condition. Particularly a transition from a lesser jet to the main jet in the carbs.
Depending on how severe the problem is it could be as simple as adjusting the the main jet needles and synchronizing the carbs and richening up the idle air screw a bit.
Remember that all general service basics should be checked before adjusting carbs. Valve clearence, spark plugs, air filter, cam chain tension, etc. should all be checked/ adjusted/ serviced/ replaced before adjusting a carb.

hi buddy set the needle clip to its normal condition and also on the carb is the mixture screw you need to turn this all the way in and out 1 turns and try this you will always get a bog if you rev fully too quick i had this problem with my kx85 and it was just this hope this helped mate i will send the pic in a mo

ok, assuming you replaced the carb header and stator with aftermarket parts, then I would say you definitely have a jetting issue. that flat spot is coming from your engine starving for fuel. its taking the gas too long to get from the carb to the engine. you would fix this by adjusting the idle mixture on the carb. the first thing I would do is look for the fuel mixture screw on the carb. im not familiar with your specific model. but the screw is usually found facing down on the bottom of the carb, directly in front of the bowl. when you find it, turn it counter clockwise about 1/2 turn at a time until that flat spot fades away. if that doesnt work, then you will need to up the size of the pilot jet inside the carb. maybe 1 or 2 sizes would be enough. if you replaced the carb with a bigger carb, then you may not be able to fix this problem. in my experience, larger carbs will increase power, but usually throttle response, especially low end, suffers considerably. the reason for this is lower intake velocity and vacuum. basically, with a bigger carb it takes a second longer for the fuel to be drawn from the carb and properly atomize with the air. hope this helps.if I overlooked anything let me know! some more info on the engine/modifications and carb/jet sizes would help too. good luck.