Main Bearing Sets

The crankshaft rides in the main bearing. We prefer the Silver Line brand, as they have metal backing.  Note: Scribe a line on the outside of the case in line with the dowel pin on the rear main bearing. Also scribe a line on the outside of the rear main bearing. When you install the crank, line up your marks. When putting the main bearings on the crank make sure the dowel pin holes face the flywheel. Use oil on the I.D. of the bearings and squirt some on the journals of the crank before putting them on. Crank size goes as follows for 1200 to 1600; 2.165 to 2.164 is std.; 2.155 to 2.154 is .010; 2.145 to 2.144 is .020; 2.135 to 2.134 is .030. The case size goes as follows (outside of big bearings) 2.560 is std; 2.580 is .020; 2.600 is .040; 2.620 is .060; 2.640 is .080. Thrust cut is the measurement of the saddle where the rear main rests. This is very important. Your rear main has to fit tight on the sides or you will soon have problems. Sometimes it is necessary to cut a bearing to fit the case. Sizes are as follows: .866 is std; .826 is +1; .786 is +2. When reading the description sizes go in order of crank, case, thrust.