Hello, sorry for the dumb question here, I?m just stumped.I have a Deere 4040 that I bought that was sitting for about 10 years outside. Tractor has higher hours, around 9 k, but did not use any oil. The tractor however was parked because it started to get antifreeze in the oil. I pulled the head off, found a bad head gasket as well as 2 broken head studs. I had the head machined, redid the head studs, new head gasket, put it together, not getting antifreeze in the oil anymore, so that problem is fixed. However, the tractor just runs crappy, and doesn?t seem to have a lot of power at all, with white/grey smoke. With that, I replaced the injectors, cleaned fuel system out, which seemed to help some, just not a lot. It?s still running rather ?choppy? and hard starting. I?ve got a 4430, which sounds way smoother than this 4040. Now, the tractor has a m and w turbo on it, which was in it from the day it was new. I know it?s hard to tell without seeing it, but what should I be looking at next? Think the turbo possibly? Any checks I can do or try? Sorry for the dumb question, just looking for some advice on what I should be looking at. Thank you in advance for your help.