13-1. FUEL SYSTEM/CARBURETOR/ FUEL PUMP/ FUEL TANK GRAND DINK 125/150 Remove the two vacuum chamber cover Screws screws and the cover. Vacuum Chamber Cover Spring Remove the compression spring and vacuum piston. Vacuum Piston Vacuum Piston Diaphragm Remove the needle holder, spring and jet needle from the piston. · Be careful not to damage the vacuum piston diaphragm. VACUUM PISTON INSPECTION Inspect the vacuum piston and jet needle for wear or damage. Inspect the diaphragm for deterioration and tears. Jet Needle Spring Needle Holder 13-8