i use maxima castor 927 in tank although i recently questioned myself when i had my cr125 manual it said castor oils where unnessesary and might cause pre-mature wear or something like that although the manual also says br9es for plug and anyone who ever owned one knows that it needs the br8es to run but first time i heard of that ...but like i said it was in the cr125 origional manual.....im still running castor 927 $$$$$$$$