My 250 runs 2550 rpm @ 70 mph with a 28" tire with an automatic T350 trans, so no down shifting. Try the same hill in 4 gear, if it still " looses power " then look for a lean condition, maybe your fuel has changed in your area or the carbs have blockage you haven't got cleaned out yet. Check the distributor and make sure it's timed right and the advance isn't stuck. I doubt the muffler is plugged up, but check it along with dirty air filters, especially if you have those really small diameter dual filters.
If you haven't done so in a while, run up to full rpm through the gears to get it " cleaned out " as we used to say. They need run every so often, my dual Carters need it often if I don't drive it very much. After a good run up, mine idles much smoother and just runs better till it sets for a month or so.
Last edited by Joe H; 09/26/2023 1:13 PM.
