Main Bearing Clearance

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

1. Remove crankcase.
2. Clean bearings and main journals.
3. Place a piece of gauging plastic to full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.
   Fig 1: Placing Gauging Plastic To Full Width Of Bearing On Journal

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

   Tighten crankcase bolts gradually as follows.

   1. Tighten crankcase bolts (10 mm (0.39 in.) thread diameter to 42 N.m (4.2 kg-m, 30.5 lb-ft) according to numerical order in the figure.
   2. Loosen all bolts until tightening torque is reduced to 0 in reverse order of tightening.
   3. In the same manner as Step  a, tighten them to 42 N.m (4.2 kg-m, 30.5 lb-ft).
   4. In the same manner as Step  a again, tighten them to 60 N.m (6.0 kg-m, 43.5 lb-ft).
   NOTE: Tighten 10 mm (0.39 in.) thread diameter bolts first (following the order ("1" - "16") shown in Fig 2), then tighten 8 mm (0.31 in.) thread diameter bolts.

   Tightening torque 

   Crankcase bolt (10 mm (0.39 in.) thread diameter) (a): Tighten 42 N.m (4.2 kg-m, 30.5 lb-ft), 0 N.m (0 kg-m, 0 lb-ft), 42 N.m (4.2 kg-m, 30.5 lb-ft) and 60 N.m (6.0 kg-m, 43.5 lb-ft) by the specified procedure Crankcase bolt (8 mm (0.31 in.) thread diameter) (b): Tighten 27N.m (2.7 kg-m, 19.5 lb-ft) by the specified procedure

   NOTE: Do not rotate crankshaft while gauging plastic is installed.
   Fig 2: Tightening Bolts In Sequence

   Courtesy of SUZUKI OF AMERICA CORP.
5. Remove crankcase and using scale (2) on gauging plastic envelop, measure gauging plastic 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

   Standard: 0.024 - 0.044 mm (0.0010 - 0.0017 in.) 

   Limit: 0.060 mm (0.0023 in.) 

   Fig 3: Measuring Main Bearing Clearance

   Courtesy of SUZUKI OF AMERICA CORP.