i lost 1 1/2 cup of coolant after 2 hours of hare scrambles(70% tight wood). my yzf 450 2006 is stock and had about 10 hours before that race. it's my first time on a 4 stroke and i have not race in 15 years. you guys helped me choose the best one. i just love it. it really makes me feel 10 years younger. do you think i could have damaged my engine with 1/3 of the coolant out? what should i do to prevent that? thank's again!