Engine

Engine Rebuild #6 (Crankshaft, Primary, and Timing Chains)

This is the last major video prior to putting back together the two halves of the lower engine case.  This is the first major milestone of the engine rebuild!  Some tips below in installing the crankshaft, primary, and timing chains.

  1. Go ahead and replace the chains.  Get the cryo treated chains.  They are a little more expensive but will last longer and stretch less.  I got mine from CycleXchange.  Parts are around $90.
  2. Replace the oil seal at the end of the Crank Shaft.  There are seven (7) total that need to be replaced on the CB750.  Buy a kit.
  3. Check the bearings on the rods (placed between the rod and the crankshaft).  I chose not to replace mine due to three reasons.  1.)  Finding the rod bolts are pretty difficult and expensive.  With the rods and bearings, it’s probably going to be about $250 to replace the bearings with the new bolts.  You MUST replace the bolts if you disassemble the rod because they are stretch bolts that are designed to be used only once.  2.) the bearings between the crankshaft and the case were not close to be out of spec when I measured them with Plastigauge. So, it was unlikely that the rod bearings would be.  Also, there was some horizontal wobble, but no vertical (up and down) wobble of the rod with he crankshaft.  Here’s a good video on this check.

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