Honda-SOHC

I own a 1964 CB72.  The Honda workshop manual shows a method for removing the camshaft from the cylinder head: take a plastic hammer and a drift and hit the outer race of the camshaft bearings.  I did this as a teenager and the method is likely to damage the bearings.  Much better to warm the cylinder head with a hair dryer for 10 to 15 minutes.  Differential thermal expansion allows the steel bearing races to slide easily in the aluminium housings.  That is, the aluminium housing expands more than the steel bearing when heated.  50 to 60 degrees centigrade is usually enough to allow the bearings to slide while not being too hot to hold.