hello, I picked up an RS250 and am having trouble with it stalling. When it's dead cold, like first thing in the morning it starts up pretty easy, but then after it warms up a bit and I take off, without fail 5 minutes in to the ride if I pull up at a set of lights or something it stallson me and then the only way I can get it started again is pushing starting it. it doesn't matter if I have the choke on or not, I get nothing - apart from giving the old legs a good work out it's a pain as well as being embarrassing! One night this week I had a bit of a run where it just kept stalling on me. Any thoughts?