What kind of machine is it??
There are VIN decoders all over the site..the VIN should be located on the steering neck behind the headlamp. Usually just stamped into the metal.
Most machines have a standard 17 digit VIN, others like the Yamaha don't..the decoder listing is different for each.
Current toys..
1986 Honda 350X..trail bomb!
1985 Honda 250SX..my main mudder
1985 Honda 250ES..Back in Black Trike
Current non-trike toys:
1990 Honda TRX300FW
1995 Seadoo GTX
1998 Polaris Indy Lite 340(Nearly new looking)
1998 Polaris Touring 500
1998 Club Car (electric)