Baught this bike for my wife a few yrs. ago. It's always been hard to start, when cold, & very very cold natured. Always runs fine after warmed up, and restarts easy with just a touch of throttle rest of day. A couple of weeks ago, I put appx. 8 oz. of Sea Foam fuel additive in a full tank of gas. Everything fine till a couple days ago. Bike is starting good, but won't idle worth a flip after warmed up, constantly blipping throttle to keep it running. If it dies, won't restart at all. Won't even hit a lick, even with a shot of starting fluid. Next day, when completely cooled down. Full choke, touch the start button & it fires right up. Hoping for suggestions, short of pulling the oddball 2bbl. carbs.