on the back bar on the LEFT side next to the tail light- there should be a metal tag tack welded to the frame facing out that's the same color as the frame and easily distinguishable. The left side is based on sitting on it and looking forward- it is your left then for those who get confused.
The model designation is located on the left rear upright on the frame. This is stamped in the tube behind the rear tire. It is a 13 digit of letters and numbers. You then have to take this to a Suzuki dealer to find out the year and model of your unit. The ID of my Suzuki 250 Quadrunner 4x4 1992 is JSAAJ45A1N2100642. Hope this helps.
2006 Suzuki LTA700XK5
What year is my Suzuki DR 250 with VIN NumberSJ45A102114
http://www.atvstyle.com/index.php/atv-vin-number need to know the year a bike was built
1997 Suzuki LT-4wd
1987 LTF230
Try using this decoder: http://www.motoverse.com/tools/vin/suzuki.asp
1990 LT-F250
Model year 1992
Js1rj18c
1992
You can find the VIN number on the frame at the steering head.