Hey guys need some advise I've just bought a beta Evo 300 4t 2014 when its cold it backfires really loud is that normal? I had a delay in 4th like a bogging so I took it to the garage and they said the airscrew was only 1 and a half turns , it seems better since it has come back but it still does it slightly I was kinda hoping the backfire may mean something , it sound ok when it's warm but I can still feel something is not quite right , any help would be much appreciated

You have to drop the needle clip down to the second last or last position. The Beta 4T come lean from the factory to pass emissions.

Cheers matey I will give it a try

As Billy said, Sounds like a lean condition, Chuck a new plug in too as 4t's eat them.

Yep sounds promising but how the hell do ya get to it haha it's not like a normal carb !!!

You VERY carefully take off the big black cap on top of the carb  and underneath is the rubber diaphragm and slide.

 

The clip will be on the needle.

 

BE VERY CAREFUL when putting the black cap back on you don't pinch the seal.

Yep I've managed it , it was on the 3rd from bottom so I've moved it to second from bottom , it sounds mint but don't know until I have a go tomorrow , thanks for your help , life savers

Worked a treat like brand new , thanks again guys