hi i am have some troble with my bike it is a yam sr125 1994 it keeps cutting out when i am riding it some times it will start  and some times it wont  but i have tried every thing i can think ov i am good with bikes and cars but this has got me stumped 
 
 
(thing i have done) 
 
new carb second hand  
new ht lead and cap 
new spark plug  
coil 
cdi unit  
cleaned the tank new petrol  
cheaked all the wirering