Oh god, an oil thread!

[rearwheelslider]

I use a lot of 2t oil in my dirt bike, CR250. Since it has a powervalve, a non gummy synthetic is the best option. R50, Maxima K2, Motul 800, redline are all good options.
For the RD, I will actually be premixing a similar potion. R50 or Maxima Castor 927... The 927 is fine for a non powervalve engine in my opinion. Good smell, good protection. I will probably run that in the aircooled...

[Vintagewannabe]

After reading this thread I want to try something other than yamalube, but I am nervous. If I switch to something like bel-ray SI-7 or bel ray mineral, is there going to be a problem with that and the yamalube mixing? Are there any oils that absolutely cannot mix?