Yamaha TZR250 modified carburetors

The carburetors are modified. The small steel ball that blocks the airpassage is removed from the backside (left is the pilot air jet, next the hole where the ball was pressed-in) These carburetors have a backplate that can be taken away, very easy! After that the first part of this hole should be re-drilled in steps up to 2,5 mm. Next the normal hose outlet should be blocked in some way. I simply glued a ball into the hose and cut it off. I use a 260# mainjet, 5EJ48 2nd step jet needle, P-8 needle jet set and a 27,5 pilot jet.