i had sorta the same problem when i first brought my baby home from the country :D

rough running, spluttering when i wound open the throttle, irregular idle, hard starting from cold ect ect.

after a much needed full service my mechanic told me that it took near enough 3 cans of carb cleaner to flush out my carbs lol.

thanks peeps, thats helped me alot, ill let u know how i get on! :D