Motul 5100 is very good oil and it even smells good. There is only one way to know how well your oil is doing and that is to have it analyzed. http://www.blackstone-labs.com/
Reports in their forum show C14 puts fuel in the oil so they recommend oil changes based on that issue. Apparently Kawasaki is using the same trick as Harley, when the bikes cylinders get hot it adds extra fuel to cool them off.
One time I went 10k miles on Amsoil in my C10 and it came back as still able to go another 2k. I get the full metallurgy analysis done and shearing was minimal.
I have not done the C14 yet but I will change to Motul 5100 first and then get it tested. I find the bikes shift much better on Motul then with Amsoil.
I ran back to back Blackstone analyses on my 08 C14 at 6000 +/- 500 mile intervals with Rotella T Synth 5w40 and Motil 5100 15w50 and other than the viscosity the Rotella had the better results. Blackstone suggested increasing interval with Rotella but not with the Motul. I did not notice any difference in shifting.
ROTELLA:
"This first sample from your Concours is looking really good. Universal averages show typical
wear levels for this type of engine after about 3,000 miles on the oil. That fact that wear metals are looking
this good after almost twice as long on the oil as average shows an engine that is wearing very well. A little
fuel dilution was present, but that's not unusual in bikes, and 0.5% isn't cautionary. The viscosity was in the
5W/30 range. Fuel may have thinned it out a little. The TBN was strong at 6.2 showing lots of active additive
remaining. Try 8,000 miles on the next oil."
MOTUL:
"This second sample contained quite a bit of silicon, and wear increased more than expected
after the longer 6,542-mile oil change interval. The silicon could be abrasive dirt causing the extra wear, so
suggest checking the engine air filtration system for cracks or loose fittings. Lead was the only metal reading
far enough out of line to highlight, but that could be from a one- time particle streak through the bearings so
we'll look for improved lead next sample. The slightly low viscosity isn't a problem. The TBN was a strong
4.8. Stick with 6,500 miles next to monitor."
