Hello Johhnycowboy,
1976 XT500 Yam fits in Period 2 Middleweight Production.
The Period 2 Middleweight Production starts on page 30 of our rule book which is on our new website.
http://vrra.wpengine.com/wp-content/upl ... -Final.pdfMaximum model year 1976, except as listed in the exceptions. This class is limited to any machine originally sold for street use and subsequently modified for road racing. Any component that is visibly different and/or uses technology not available within the period must be submitted to the Technical Coordinator for approval.
Up to 400cc single, twin and triple cylinder 2 stroke
Up to 500cc piston port twin cylinder 2 stroke
Up to 600cc single cylinder four stroke
Up to 550cc SOHC four stroke, 4 cylinder
Up to 550cc SOHC or DOHC four stroke, 2 cylinder
Up to 650cc pushrod twin cylinder four stroke
You should read this section over P2 Middleweight Production has some specific rules about production frames.
Period 2 Middleweight Production maximum model year 1976, except as listed in the exceptions.
TX500 and XS500 are allowed as exceptions through to model year 1978.
I believe the SR500 first came out in 1978 and would then fit into the P3L class.
So you can do a lot of bump ups with the TX500 and XS500
Kind Regards,