The answer is yes. Carleton Palmer began using synthetic oil in his racer about 30 years ago (Mobil 1) and I followed his lead. Neither bike experienced any problems at any time that was due to oil failure. There were some mechanical failures. Specifically, we ran into problems with the hardened washers on either side of the conrod. When the conrod developed side thrust it had the possibility of gouging the hardened washer, which in turn could leave a scar in the hardened washer. The scar would catch on the conrod and cause the washer to turn at high speed. The friction would overheat the oil which would cause failure. We substituted a phosphor bronze washer for the hardened washer. The phosphor bronze washer was much more resistant to "catching" on the conrod if the washer became damaged. I don't think this is necessary on a street bike, but I mention it for full disclosure. Most of the racers use this mod, but the singles are shifting at 7000 RPM.
I think that the other components looked good because there was proper lubrication.
I received a call the other day from my guy who does the flywheels. I had sent him a brand new flywheel and asked him to check it. When he pressed it apart, too easily in his opinion, he found that the timing side conrod clearance was zero and the drive side was fine. The lack of clearance on the timing side already had created a scar. So, it does happen.
David
