bike has been sitting since the end of 05. i have got it running again but it is smokey on start up when it is cold. when its warm, it is fine. the recommended oil is 10W 40, should i change the oil to say 15W or 20W 40 (or even 50) so it is thicker? is it likely that it is only smokey because it has sat for so long and needs "wearing in" again (and a good highway blowout)? could it be the valves (or valve seats) that is likely to be the cause? without the obvious "needs new rings" as i dont believe that this is the case at this point of time. i know that all of these options could fix the problem, but which is more likely to have better results? in a car i might try a heavier weight oil to reduce smoking or replace the valves/valve seats if it was smoking at cold or idle. ive never bought a car that hasnt ran in a few years, so i cant comment on that part of the question.