hi need some help!!! my yamaha dt 125x has been giving me loads of grief lately basically it wont run write when i fire her up she runs fine on choke but when i take the choke off it runs down the revs and cuts out the same way as if i ran out of petrol but its tempermental i tried turning the tickover up that helped then when i take it out on the road as soon as i give it over half throttle it tries cutting out so i either have to keep to 40 or ride the choke!! also the other day i went out it seemed ok so i gave it some throttle to see howw ok it was got to 70 then it just lost all power. i dont have loads of money so i dont want to take to a garage n they say itl cost 300 to fix. please help any ideas????????