Don't have a clue, sorry mate :/
9.2:1
SR250 pre 1981
That depends on what brand and what model it is and also what kind of shape its in. The average price in 1982 was much lower for example. Comparable bike. 2007 Yamaha YZ2501-Cylinder2-Stroke249ccS.R.P $5,110 1982 Yamaha SR250 Exciter1-Cylinder4-Stroke250ccS.R.P $825.00 Source = http://www.kbb.com/kbb/Motorcycles/Retail.aspx Hope This Helps.
There are two 10mm bolts on either side of the bike that hold the side panels and the rear of the seat to the frame. Remove those two bolts, and then slide your seat rearward, because there is a plastic tab that holds the seat to the gas tank. Installation is reverse. Slide fwd, install bolts. It must depend on the model because mine is different. Mine has two latches; one on either side of the seat, with a lever on the left one located just behind the side cover. The lever pushes the left latch forward and the left latch is connected to the right latch by a bar which runs under the seat. You might have to hold the left side down while unlatching because once it pops out, there's no connection the the right latch anymore and so it might stay latched on that side. Once both sides have popped up, slide the seat rearwards.