I just weighed my bikes. My '86 TT350 weighed in at 267 lbs with about .5 gallons fuel in the tank, that would bring it to right at 280 with a full tank. The bike is fully street legal, battery and all. My '80 TT500 is 297 lbs with about 1 gallon in the tank, also fully street legal.
Do it in the Dirt!
1974 DT250, 1980 TT500, 1986 TT350, 1993 KLX650C, 03 KTM450EXC