I found this tech Q/A in an old Cycle world I just got off eBay. If I owned a 450 at that time I would be pretty annoyed at this problem!! It's almost a forerunner of the VFR problems which were to follow.
Q: My problem concerns my Honda CB450, which has about 9,000 miles indicated on the odometer. I recently noticed pitting at the high point of the right cylinder exhaust cam.
I have performed all maintenance requirements and have always used a good grade of oil. My machine is ridden normally, with some turnpike and some back road driving.
Is this a problem common to the earlier model CB450’s? Is it a design problem, i.e. insufficient lubrication or soft spots on the cam? Is it possible to correct the problem without major modifications?
A: Problems such as your occur in the Honda CB/CL450 models and are caused by an insufficient layer of Stellite facing on the cam lobes. Stellite is the trademark for a hard facing material composed of 75% to 90% cobalt and 10% to 15% chromium, with or without added amounts of other materials. It is used for cutting tools and other wear resistant surfaces, such as camshafts and cam followers.
Since camshaft lubrication of these Honda models is more than adequate, the only way to reduce wear is use a good grade of single-weight, high detergent racing oil of the correct viscosity rating for the outside temperature. Warming your machine up by riding slowly for the first few miles after starting fro cold will help prolong the life of all of the components in the engine which are lubricated by engine oil.
Replacement camshafts are available at a reasonable price from your Honda dealer, and, with reasonable care in warming up your machine they should last a long time. If the problem really disturbs you, it might be a good idea to write to a camshaft specialist in your area and check into the possibilities of having your camshafts reground to stock specifications and re-faced.
