Hey can anyone tell me what plugs the GSXR250-400 should be running?? (I'm pretty sure the 250 and 400 will run the same plug)

Does an NGK CR8EK sound right? They are a long reach plug.

I can contact a bike shop tomorrow during working hours but just after a quick answer tonight.

GSF 250 is VERY similar engine wise.
Take a look here -
http://www1.synapse.ne.jp/s-hara/bandit/ban-spece.html

Thanks mate. I purchased a set of NGK CR9E spark plugs and they work a treat!