This is a flat 6 cylinder motorcycle engine (1520 cc) that shares the oil with a 5 speed trans. It also has six carburetors. Oil has been in service 1 yr, with 1387 miles, and 13297 miles on the motorcycle. The cycle is used about 80% highway back and from work which usually includes a brief 3 mile ride on the last leg of the trip at 75-95 mph after hard acceleration onto I-95. This happens on the way home also but the bike is not as warmed up (2-3 miles before on ramp). The remaining is local riding including errands, 40-50 mph max. Stock Honda air filter and oil filter. Air-filter has rubber seals both sides. Evans anti-freeze. Amsoil recommends 3x manufacture change interval (which would be 24k miles) or one yr. This oil has been in the bike since 7/9/03. This oil saw summer (90+ degrees) and winter (30 degrees). This is my first OA. The oil before 7/9/03 was Amsoil 10w40. Sample was re-moved by a brand new plastic siphon hand pump from harbor freight. Per Oil Analyzers (ppm); iron 17 chrom 1 lead 0 copper 19 tin 0 alum 5 nickel 0 silver 0 silicon 9 boron 2 sodium 5 magnesium 20 calcium 3734 barium 0 phosphorous 940 zinc 1357 moly 0 fuel 1.5% Vis @100 C 11.29 Glycol neg water 0% TBN 11.78 OXID 15.00 NITR 12.00 Lab comments: No corrective action required, oil is suitable for continued use. Re-sample at next regular interval. My comments: I have limited knowledge on OA, so any help will be appreciated. About half of the 1387 miles were put on this yr. The carbs were not adjusted correctly which has been corrected but were not off that much. These bikes tend to run rich at idle to help get its 750 lbs plus rider moving. From learning on this board I take it that the fuel dilution would have caused the drop in Vis from a 40w to a high 30w. As a result of this I replaced the oil filter with a larger one which required about 1/2 quart for makeup. This is a 4 qt system. I do not know if the metals should be a concern or not, since these engines are known for 500k miles of service. When should I re-sample or change the oil? What does OXID and NITR represent? Are they a concern? Thanks.