I'll try to make this as short and sweet as possible. I'm rebuilding a '84 Johnson 6hp. A machinist friend of mine has the block and crank ( stripped crank/drive shaft spline repair)<br /><br />When I yanked the crank I noticed that the center main crank journal looked a litttle discolored, not much, but signs of heat. This center bearing (30 needle bearings in clamshell carrier) is lubed thru a .042 oil port from the bottom of the top piston bore. <br />The bottom piston bore has an oil port too that supplies the lower main ball bearing.<br /><br />Looking at the bottom cylinder oil passage, I noticed that it is drilled at the lowest possible point which allows pooled oil to feed the lower main ball bearing. <br /><br />The top cylinder oil port ( feeds center main crank needle bearings) is drilled a good 1/8" above the lowest point in the casting. This I see is the problem. Oil has to pool at least 1/8" before it reaches the oil port before it gets 'pumped' thru to the bearing carrier on the power stroke.<br /><br />After the long winded description above, here's my question. It seems to me that the oil port was drilled too high, starving the center crank bearing. Would you advise redrilling another oil port below and parallel to the original allowing the oil to reach the bearing without puddling. I know that being off 1/8" isn't much in so many things, but it this case, I think it's going to mean the difference between toasting the bearing.<br /><br />BTW, all of the bearings and journals looked really good and are within specs except for the middle crank bearing.
