Look on the rear frame vertical bar. theres a tag "suppost" to affixed to the frame (Mine starts with JAA and the final letter is "H". Hope this helps.
1987 LTF230
2006 Suzuki LTA700XK5
http://www.atvstyle.com/index.php/atv-vin-number need to know the year a bike was built
1997 Suzuki LT-4wd
Try using this decoder: http://www.motoverse.com/tools/vin/suzuki.asp
1990 LT-F250
Model year 1992
1987 Suzuki LT500R
Yes
The VIN is stamped on the frame and can be seen looking between the left rear tire and the fender
2002. I used the source link to decode
1996 LT-F4WDXT King Quad