Metal shavings indicates severe wear, in most cases. If you had the metal shavings analyzed, you could determine which part of the engine is wearing, based on the type of metal.
Oil analysis will determine this for you, at a cost of around $22-$30.
What type of oil, and how often do you change it? I go for the best, for the least amount of cash, out of pocket:
Shell Rotella T6 Synthetic 5W-40 (labeled as "Synthetic", but actually just a highly refined dino oil, which acts like a full synthetic, good for 10,000 miles between changes), around $5.50/quart, or $21/gallon, at
Wal-Mart,
Mills Fleet Farm, etc. Even if you go with the
Super-Tech brand (
meets API standards, will not void a new car warranty, so,
yes, it is safe to use), from
Wal-Mart, as long as you change it every 3,000 miles (with a new filter...), you won't have wear issues caused by degraded oil. If you are paranoid, go with the least expensive oil (
Super-Tech 10W-40, around $3(?)/quart), changed out every
1,500 miles (with a new filter...).
Whatever oil you choose, be sure to change it more often, if the metal bits continue.
Always change out the filter with every oil change... The filter will capture the metal bits, but at 72 PSI, I would want them removed as often as possible, to avoid compromising my filter. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII