gearing might come to play. I have the GS-R tranny bolted on. Gears are considerably longer but I thought it would help at freeway speeds. Anyways, I can't figure it out. The only thing I can think of is that it's running too rich. Because I notice now every morning, my engine doesn't rev up to 2000 rpm like it use to and slowly drop below the 1000 mark. And I can smell raw gasoline while it's warming up trailing it's way into the house while I'm brushing my teeth. Talk about carbon monoxide poisoning!!!!!!! But running too rich will only bog the engine at low speeds. At the high rpm I was running last night, I don't see any issue of rich mixtures coming to play.