Examination
1. Remove the diaphragm from the cylinder.
2. Disconnect the lever rod, remove the axle. Attach a hand vacuum pump to the top diaphragm fitting.
3. Create a vacuum of 400 mm Hg in the diaphragm. The diaphragm rod should move 22 mm. Otherwise, replace the diaphragm.
4. The vacuum must be maintained in the diaphragm for at least 30 seconds. Otherwise, replace the diaphragm.
Replacement
1. Disconnect vacuum hoses.
2. Loosen the bolts and remove the diaphragm from the crankcase.
3. Installation is carried out in the reverse order.