Hey guys, I've been browsing the forums for quite some time now and just decided to create an account. I'm requiring some help with my newly purchased g6200. I am at a total loss here. I have read countless posts and can still not find a solution. I purchased my g6200 with 54" deck for $350 from an older gentlemen because it had been sitting for a total of about 6-8 years. Within that time he had it serviced and tuned up once and yet again parked it. When I bought it the battery was dead and we just left it at that. Took it home, threw a battery in and it started up. I drained fuel, oil, and hydro oil. Changed all filters; oil, hydro, air, and both fuel. I also ran diesel clean and mmo through it. Tank looks to be very clean when I shine a light in it. Now here's my problem. It is a little rough to start but I'm not sure the glow plugs work so I'm not too concerned with that but it is very low on power. When I engage the mower deck, the rpms drop about half and I can only drive about 1-2 mph without it stalling out. I have taken the mower deck off to make sure nothing is hung up and engaged PTO without the deck installed, all is well. While it is chugging, it is blowing a decent amount of black smoke, but nothing I wouldn't expect for how hard the engine is working. Does anybody have any idea what could be the problem here?