Yamaha RT3 1972/1973 Forum

hey just bought a bike im pretty sure it is an rt3, vin- RT1-125557
I know it says rt1 but i looked up the vin and it comes up as a 1973 rt3, i dont get it

some help??

http://images.craigslist.org/3n93p93l45Y55Q25R2a9rcb29e570ba3c1dce.jpg

http://images.craigslist.org/3n33ob3p15O05Z15X3a9r949dfa52332c17c5.jpg

the front fork must be after market because it doesn't have the head light mount , but then makes me think t might be ab rt1 MX ??