Originally Posted by smokeeater495
I hope your homebuilt spacer works for you. I read a test where a guy put an FCR39 on his XR650L with an exhaust pipe adapter and it ran like crap. Google "Noss adapter". It attaches to the intake side of the carb and provides a smooth transition. The 37mm carb should have awesome low end snap.
Part of the XR 650 guys problem could of being getting the pipe to properly seal... I pressed mine on with retaining compound and once I get the thing fully cleaned up I will add a bead of sealant around the pressed on rim just to make sure air can't leak in...
I was going to get my machinist friend to make me up an adapter but he was busy at the time so I figured I would try the SS pipe for a start... Even without the adapter the FCR has quite an abrupt entrance into the bell... The SS pipe really doesn't change anything with that except adding a longer throat to the airbox... If it turns out to run poorly I'll think about adding a stabilizing vane to the throat...