When I broke in my 08 ZX-14 I changed the break-in oil at 580 miles. I was really surprised at the silver color of the oil and could only imagine that the OEM filter did not do it's job. Why would I be looking at all of this stuff floating around if the filter had trapped all of it? This time around with my 2012 I decided to replace the filter at 300 miles and let the sulfur smelling oil, that is formulated to help the gears break in, do it's thing. The stuff that I dumped at 638 miles looked much cleaner than the last time around but it took two filters to do it. Kawasaki calls for oil changes at 7500 miles or 1 year. The Amsoil people have come up with an extended filter good for 15K miles(new product I have not used yet) and for motorcycles call for Synthetic oil changes at 15K or yearly, which ever comes first or you can run extended changes at twice the manufacturer's change period. With Kawasaki that would be 15K miles. I buy the Amsoil SYN 10W-40 engine and trans lube and I change it each year. It cost about $9.50 per quart. I use the Purolator 14610 or the OEM filter and prefer the 3.5 inch filters over the shorter ones. The Bosch 3323 and Super Tec ST7317 are also good. I rode the 08 for 48-49 months and put 49240 on her, she has almost a year of warranty left and that will transfer to the new owner. My green 2012 already has 3648 on it now. Oil and filter changes for the 08 for the 49K cost me about $237. If I had changed it every 877.3333333 miles, it would have cost me $3327. Ride till you die.

I still use Dino oil and try to keep it down to every 2k, never more than 2500 mi. I use Valvoline 4 stroke motorcycle oil or Castrol 4stroke if I can't get the Valvoline. To each their own.

I used Amsoil MCF 10W40 exclusively. After my 2012 Concours 14 ABS is broken in (4k miles) I will switch it to MCF 10W40 too.

I said a long time ago even with 12,000 mile riding seasons, I only changed the oil in my ZX14 once a year, at the end of riding season before I winterized.

Amsoil says I can do that, and has the test data to back it up.

Anyway, I traded the ZX14 in on the C14, and last week the shop at my dealership took the ZX14 pretty much apart to check it because they have a hot prospect who wants to buy it, but wants a 1 year warranty on it. Fair enough. So my very good shop tech (he makes anyone here look like rookies, and even Harmon, the Tech guru in COG) told me when I was in there this week that the valves are pristine, everything is well within tolerance, no adjustment needed, piston crowns are clean, and when they pulled the filter (which had a magnetic ring on it, as does the drain plug) there was absolutely nothing sticking to them.

I have to say near the end of the riding season the clutch got just a bit heavy (not bad, but I noticed) so it was losing visosity finally. Looks like I will be changing the oil twice a season on my Connie, because I'm going to be doing more than 12,000 miles this season. So probably MCF 10W40 at 4k miles, and then at the end of the season to winterize it.

I'm not interested in an oil war, all of it works great if you change it when it needs to be changed. We just have to avoid stuff with friction modifiers since we have wet clutches. So definitely buy motorcycle oil, specifically.

+1 on Kawasaki Synthetic, it is probably Motul or Castrol synthetic re-badged, so very good.