OK then change the plugs and try again. My suzuki Bandit is always a pig to get going after a winter lay off, I have to leave it to warm up and at first it doesnt fire on all 4. However as it warms I find i can open the throttle more and more until it runs properly. During normal use though I dont have to do any of this. Good luck, Oh and an oil change would be advised soon as well (check the level at first oppotunity)