When I left AHRMA racing in the late 90's, the evo classes were just beginning to surface locally with non AHRMA affiliated/sanctioned clubs offering them. I am aware of the current popularity of these era bikes, and I am toying with the notion of returning to vintage racing next year. I havent decided between air cooled vs water cooled bikes. My concern is that the those water cooled bikes in being some 25 years old, are fraught with more damage/wear brought about by the use of liquid cooled motors. Difficulty in locating parts for the pumps, damage to an idle motor , the result of it being left with significant rust or oxidation. Or am I worrying too much. I recognize that for the short motos, a liquid cooled motor doesnt have much, if any advantage. Even if it did, the AHRMA classes are seperated. But some of the liquid cooled models did incorporate mechanical advances that do make for a bike thats ergonically more in line with whats offered today, along with slightly better suspension, ie Full Floater Suzukis, etc..