I put an electric fuel pump on this morning. Then, I hooked up the trailer with the ATV and went down the same roads that I was having trouble with before. While it does slow to about 50 mph on some of the long, really steep hills, it never stalled. On the straight aways it ran 65 mph without any trouble. I hope that fixed it.

1988 Raider, 2.6L (Weber carb, PaceSetter header, Centerforce D/F clutch, 5-Speed M/T, 33X12.50 Pro Comp M/T, 15X8 US Wheel 97 Series)
3" Body Lift