Building the new intake. Started out with 2.5 inch tubing, Got to cut out for the frame, weld in a plate in the tube to stop the engine from getting to much air.. This was the part of the bike that i got the most problems with, due to the extreme small space i got to work with. In metric system the measurements are 63,5 mm in the filter end and 57 mm in the other. To fit the carburator.