I purchas ed a 2006 john deere 997 diesel mower with a 6 foot cut. It originally would not start I jumped the cylinoid on the injection pump and it started after jumping the cylinoid a couple of times it started to work From then on it soon so that problem seems to be fixed. The problem I have now is that it doesn't seem to have any power when I engaged the deck. The fuel filters have all been changeD about 10 hours ago from the previous owner a municapality The only thing I'm not sure of is the water fuel separator looked like it had never been touched when I sprayed the mower off for the first time time. From what I read on here I was expecting this mower to have great power and speed when cutting the grass however it bogs down in 5 inches of grass where my 757 with a 60 inch 25 hp kawasaki would have to went through 7 inches of grass without slowing down. The diesel doesn't have any black smoke at all and the air filter looks new as well the motor was supposedly rebuild 300 hours ago and I did check the valve adjustment which was fine also. What should I be looking for power wise problems?