2000-2003 Honda TRX350 Rancher factory service manual, Page 90Get this manual
FUEL SYSTEM Be caref ul not to damage the jet needle
Install the diaphragmvacuum piston into the carburetor body by aligning the tab of the diaphragm with the air passage, then insert the jet needle into the needle jetLift the bottom of the piston with your finger to set the diaphragm rib into the groove in the carburetor body
Be caref ul not to pinch the diaphragm under the chamber cover, and to keep the spring straight when compressing the spring
Install the spring and vacuum chamber cover while the piston remains held in placeAlign the concave of the cover with the air passage in the carburetor and secure the cover with at least two screws before releasing the vacuum piston