Some motors have a coolant check bolt on the cylinder or head. Take the bolt out and make sure coolant comes out, then you knlow the water jacket is full. Once you fill the radiator, run it for a minute witht he cap off to make sure all the air is out. Since it doesn't have a thermostat there shouldn't be much trapped air. I'm not a TirZ guy but this is general info about all liquid cooled 2 strokes. Great score man. Seems like all the nicest bikes come from cali. Having someone out there to check it out in person is an invaluable resource.
[FONT="Palatino Linotype"]~My Rides (to name a few) ~
1986 ATC250R, 1985 ATC350X
1985 ATC250R Missile (90% done)
1983 ATC185S
1999 TRX416EX
2003 Honda CBR600RR
1990 Yamaha Zuma
1985 XR80 w/100 motor
1967 Honda CB77, '65 CL77
1962 Puch 250 SGS
1984 XR350R (owned since I was a kid)
1972 Suzuki T350 Rebel, '73 T500 Titan
1964 BSA A65 (needs restored)
1968 BMW R60/2 mint original bike
1976 Kawasaki KH500 triple
Anybody have parts to trade for the above models?