Rotor Housings

To clean housing, wipe off sealing agent or carbon in rotor running surface with a rag and ketone or thinner. Remove rust deposits in water cooling passages.
Inspect for cracks or damage to chromium plated surface. Check for signs of gas or water leakage. Housing must be replaced if any of these conditions exist.
Place a straightedge across sealing surface of rotor housing and check for distortion, using a feeler gauge. If distortion exceeds 0.0016" (0.04 mm), replace housing. See Figure .

Fig 1: Measuring Rotor Housing for Distortion
Courtesy of MAZDA MOTORS CORP.
Check rotor housing thickness at points A, B, C, and D in Figure . If micrometer readings vary between point A and minimum value for B, C, and D by more than 0.0024" (0.06 mm), replace rotor housing.
NOTE: This excessive clearance would indicate a possibility of gas or water leakage.