A couple of questions: Why are two of the bolts larger?  What is the torque spec on these bolts for the 20B?  I seem to recall 26-28 ft-lbs.  I can’t get a torque wrench on the bolts without removing the re-drive, engine mount and flywheel, but I have a pretty well calibrated arm.

 

Al

When you add torque to those bolts, the bolts closest to them will go under torque.

 

So go through the whole torque sequence several times if at all possible. This has been the case on every engine I have built.

 

Lynn E. Hanover