Main Bearing Sets (1700-2000)

The crankshaft rides in the main bearing. We prefer the K&S brand. As of this writing, K&S bearings are hard to locate. When we can't find K&S, we use Mahle or Silverline brand bearings. When ordering bearings, we need to know the crank size, the line bore size and the thrust cut of the rear main. With that said, Aline bore bearing for this motor are getting really hard to find if at all. For 40hp-1600, measurements are as follows. 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; 2.362 to 2.361 is std.; 2.362 to 2.361 is .010; 2.352 to 2.351 is .020; 2.342 to 2.341 is .030. The case size goes as follows (outside of big bearings) 2.756 is std; 2.776 is .020; 2.796 is .040. 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. What I'm saying here is you buy an oversize thrust bearing and cut it to fit the case. As of this writing we can not get any oversize thrust bearings.