running problems have to keep revs up (coil pack?)

[lloyde]

it starts but have to keep the revs up so it doesnt cut out!and when you put your foot down it splutters and jumps!

is it the coil pack?its just had new plugs and leads!

[chris050788]

have you checked your breather pipe and the air filter coz with mine the breather pipe had come off and was doin the same.