Good eveing all,looking some advice and answers ,i have a 2005 650 supermoto with 70hrs on engine it has had crank mod,i change oil and filter every 3/5 hrs ,it is runing great pulls real strong slight puff of smoke now and again ,when i change oil i have been puting 800cc back in using motul 15/50 double ester,the last oil change was on 66hrs couple of rides up to 70hrs dropped oil and messured in jug only got 600cc out is this ok i am quite new to running bergs