I have a new 5205 with 7 hours on it. After I have warmed up the tractor and it is at normal temp and I have it in netural with no load and I put it at full throttle it starts to belch out white smoke and spit and sputter. I don't know if I have a timing problem, bad valves. or dirty injectors. I sure would like some input from a diesel mechanic or a least someone who has had the same problem or even a wild guess. P.S. Any throttle position less than full it seems to run fine.