It rises and falls, I'm trying to get it around 1200-1300 and it will stay there for a bit but then it could rise to almost 2000 or drop to 1000, at 1000 rpms its very close to stalling and I've got to get on the gas to bring it back up, the right side exhaust seems to heat up a little faster and runs hotter. I'm confident every thing is correct, valve clearance , timing, points gap, compression, carbs are cleaned with new o-rings. I do seem to have a very little bit of an exhaust leak on the right side, where the head pipe meets the engine, also a couple of rust holes all the way back on the right side muffler. Also on my left side intake boot I have a crack but I'm sure it doesn't go through, I've cleaned the surfaces well where the intakes mount to the engine and replaced the old clamps to get a good seal at the carbs. I seem to get no-where whem I'm adjusting the idle mixture screws, small adjustments seem to do nothing and then I give up turn them back in and start again, usually at around 3/4 to 1-1/4 as a start. Any ideas would be appreciated. Thanks.