I bought this bike a few months ago and had to clean the carb to get her running again. The other day I let the bike warm up for about 15 minutes before going on a ride and came out to find coolant on the ground. I usually let it warm up for a bit because it bogs out when I give it throttle before warming up. However, if it warms up first, the throttle operates correctly throughout the entire throttle pull. It hasn't leaked coolant before. After looking around the bike, it looks like the coolant was coming up into the air intake through the engine breather tube from the rear cylinder. I found coolant on the back end of the carb, in the air intake, and pooled up on top of the engine under the air intake. I checked the coolant at the cap, which was full, and tried to check at the coolant reservoir; however, the clear tube to check it is weathered and not clear enough to see the level. I have yet to add coolant, and I am going to do an oil change to check the clarity and see if maybe I have a blown head gasket. It could be as simple as it overheated enough to boil over and all I need is some more coolant or it could be a bigger issue. I also have to say the coolant that leaked out looked just fine. It was bright green and didn't seem to be burnt or have any oil in it. It didn't look like it was discolored. Please let me know if you have had a similar issue. Thanks and happy riding.