On the later models the exhaust went under the frame rail before the skid plate, along the outside of the frame rail, and then back under the frame rail after the skid plate. It continues over the rear axle and the across the back, where the muffler is located, to exit on the right side.
Nice! I have all that fuel injection stuff, but would have to alter it a bit to make it work,so it won't be going on there.It still runs, dispite all the times it should have blown up.
Sounds like the clutch is slipping.Is it properly adjusted? When you say sputtering, if that means that the engine is revving and you are losing drive to the wheels, then it is the clutch. If by slowing down means less throttle in the same gear and it has drive, it is the clutch.
Those will not come out in that condition. Those threads need a major clean up b-4 even attempting. If you have a die that will fit in there, run it down as far as possible, then work them out slowly, running them back in every 1/4 to 1/2 turn to clear the crud. If the heads are popping off you...