Hi my bike starts and runs idle no problen and revs up 2 about quarter rev no problem but when the bike is about to move or any more throttle than quarter the bike splutters and dies but if i let the throttle out again its ok plz help what could it be

If you can keep the bike running long enough to get it warm with and with no choke then that is when you should adjust the mixture,
First though start by adjusting it cold so the screw is set at about 1.5-2 turns out then run till warm set idle at around 1500 revs and adjust until it just starts to lift the revs then back off a quarter turn

Adjusting carbs on chainsaws is not to be taken on lightly, there will normally be three screws, an L screw, an H screw, and an idle scre, the L screw will increase the fuel mixture from idle to half throttle ( they are fuel screws not air screws ) the H screw will adjust from half throttle to maximum revs, start with a base setting of between one turn and one and a half turns out, start the saw and warm through, allow it to idle, if need be increase the idle screw to get an idle, turn the L screw in slowley, the revs will increase as the mixture leans off, it will reach a point where it starts to die, now back it off a quarter of a turn, blip the throttle, the saw should pick up clean, if it has a flat spot increase the L screw slightley, now set the idle so it idles without the chain moving on the bar, now screw the H screw in to get full revs, be aware this should be set with an engine rev counter, do not exceed the manufacturersmax revs, hobby saws normally run at about 12500 rpm with an idle speed of 3000 rpm.

Depending on the type of intake system, if it's a normally carburettored bike, there is an air mixture screw on your carby(s). Set this screw at one and one half turns out from being screwed to stop. Run bike till it is warm and set IDLE screw or throttle stop at optimum idle revs. Without using choke or throttle, turn the air mixture screw slowly in or out till revs build to highest level. Reset idle screw or throttle stop to set revs back down to optimum level as before. If this does not cure your problem, depending on if it's a 2 or four stroke, single or multi cylinder engine your problem may be one of many from fuel ratio, valve rocker clearance, ignition, plug range etc....specify make/model for proper info.
Cheers

culd be sucking air in the intake boot, or the throttle cable is tight or has a fray.

make sure the air filter is clean if it is then take your carb off and clen out your main jet large brass jet in center of the bottom of the carb if that does not fix it adjust your air screw on side of carb brass flat head screw turn right until tight lightly not to hard just enough till it feels snug then start at one turn left and rev 2-3 times then go a 1/4 turn left at a time till the bike revs and runs well good luck