MBW R422 - Manual (Page 15)

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Parts Replacement Cycles and Tolerances
Bearings
Replace anytime a bearing is rough, binding, discolored or removed from housing or
shaft.
Bellows Replace when they are worn, cracked, or to the point of leaking.
Clutch
Replace clutch if shoes and/or springs show signs of heat damage or if it does not
disengage below 2000 rpm.
Crank Gear Replace if teeth are cracked or if they become sharp.
Engine Components Refer to your engine manufacturer’s Owner’s Manual.
Guide Bushings
Replace if a 0.025” (0.635 mm) feeler gauge can be slid between the spring box and
the guide tube.
Hardware
Replace any worn or damaged hardware as needed. Replacement hardware should
be grade 5 and zinc plated unless otherwise specified.
Pinion
Replace if teeth are cracked or if they become sharp. Replace if the drum is scored
or gouged deeper than 0.03” (0.76 mm).
Piston (Spring box)
Replace if a 0.025” (0.635 mm) feeler gauge can be slid between the spring box and
the piston.
Piston Pin Replace if the outside diameter is less than 0.620” (15.75 mm).
Safety Decals Replace if they become damaged or illegible.
Seals & Gaskets Replace if a leak is detected and at every overhaul or tear-down.
Springs
Replace if a flat spot on the side of a spring is greater than 0.09” (2 mm). Replace if
the free length is less than 6.75” (171 mm). Replace ALL springs at the same time.