Main Bearing Clearance

Check clearance by using gauging plastic (1) according to the following procedure.

1. Remove crankcase.
2. Clean bearings and main journals.
3. Place a piece of gauging plastic (1) to full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.
   Fig 1: Placing A Piece Of Gauging Plastic On Crankshaft 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 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 specified torque.
   5. Tighten crankcase bolts (8 mm (0.31 in.) thread diameter) to specified torque.
   NOTE: Tighten 10 mm (0.394 in.) thread diameter bolts first (following the order shown in the figure) then tighten 8 mm (0.315 in.) thread diameter bolts.

   Tightening torque 

   Crankcase bolt (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 (10 mm (0.39 in.) thread diameter)

   Crankcase bolt (b):  Tighten 27 N. m (2.7 kg-m, 19.5 lb-ft) by the specified procedure (8 mm (0.31 in.) thread diameter)

   NOTE: Do not rotate crankshaft while gauging plastic is installed.
   Fig 2: Identifying Crankcase Bolts & Torque Sequence

   Courtesy of SUZUKI OF AMERICA CORP.
5. Remove crankcase and using scale (2) on gauging plastic (1) envelop, measure gauging 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 

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

   Limit:  0.060 mm (0.0023 in.)

   Fig 3: Measuring Gauging Plastic

   Courtesy of SUZUKI OF AMERICA CORP.