Main Bearing Clearance

Check clearance by using gaging plastic according to the following procedure.

1. Remove lower crankcase.
2. Clean bearings and main journals.
3. Place a piece of gaging plastic (1) the full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.
   Fig 1: Identifying Gaging Plastic Placement Area

   Courtesy of SUZUKI OF AMERICA CORP.
4. Install lower crankcase to cylinder block.

   Tighten crankcase bolts, the following sequence (1-22) in the figure. Tighten crankcase bolts to specified torque.

   Tightening torque 

   1. Crankcase bolt (10 mm thread diameter) (a):  60 N.m (6.0 kg.m, 43.5 lb.ft)
   2. Crankcase bolt (8 mm thread diameter) (b):  27 N.m (2.7 kg.m, 19.5 lb.ft)
   NOTE: Do not rotate crankshaft while gaging plastic is installed.
   Fig 2: Identifying Crankcase Bolts Tightening Sequence

   Courtesy of SUZUKI OF AMERICA CORP.
5. Remove lower crankcase and using scale (2) on gaging plastic (1) envelop, gaging plastic (1) width at its widest point. If clearance exceeds its limit, replace bearing. Always replace both upper and lower inserts as a unit. A new standard bearing may produce proper clearance. If not, it will be necessary to regrind crankshaft journal for use of 0.25 mm undersize bearing.

   After selecting new bearing, recheck clearance.

   Main bearing clearance 

   1. Standard:  0.032-0.052 mm (0.0013-0.0020 in.)
   2. Limit:  0.060 mm (0.0024 in.)
   Fig 3: Measuring Gaging Plastic

   Courtesy of SUZUKI OF AMERICA CORP.