Personally, I'd say it looked like a bearing problem, not an oil problem. Most oiling problems I've seen hve eaten up more of the motor, not just one bearing failure. The rest of that cam looks ok compared to the bearing surface.
I still use 20-50 and change it every 2500.......

 

Between the bearing and the camshaft itself, wouldn't you say the camshaft would be a harder, more durable material? Maybe the problem is the cam ( heat treat?)

Or is that the bearing stuck on the end of the cam?

 

I thought all Amsoil products are synthetic?? I'd think 5k miles on synthetic shouldn't be a problem unless all your rides are so short as to not heat up your oil...

 

You can run 5000 miles on Dino oil...

 

I agree.
Oil-related threads seem to take on a heart, and lung of their own, and some can become a raging monster.
But the culprit at the root of that cam bearing journal failure, is the inadaquete OE bearing, that contains only half of the rollers, as that of a Torrington, or Sonnax unit.
Scott

 

It's a shame that they (MOCO) uses cheap bearings in such a fine machine...I guess it's a roundabout way to get you back in the shop.

 

I didn't think they were.I'm not really a fan of synthetic oil.I change mine out every 2,500 miles.For what they cost,I don't think they are worth it.I had one mechanic tell me he has seen bearing, & lifter problems using synthetic.I think they offer decent protection,but dino is just as good.I wouldn't run any oil in a air cooled motor 5,000 miles.The oil breaks down to quick with the heat generated from these motors,especially with a bad tune, & lean conditions!!!

 

One of the main advantages of synthetic oil, is that it does not break down like straight oil. That is one of the reasons it costs more, and is far superior. As far as the failed bearing, it has been well known that the OEM style bearing is inferior, and is usualy one of the first things to be changed, when some engine work is being done.

 

Hope it all works out. I hate to see the MoCO use cheap parts in a critical system, but we know it's going on right now.......

 

Whole-heartedly agree with Rob.
Synthetics do protect the engine very well, and it has been proven as to the cooling effects they have, and even increased dyno numbers, but once most thin-up, at full operating temps, lifter pump can be compromised, resulting in unwanted engine noises, from what we have seen.
Scott