The only tachs like that are going to be digital, and they do exist. The dash tach on my '85 LTD shows changes as small as 5 rpm. The engine runs so smoothly that I can set it to run at exactly 1150 rpm, and it will hold that reading for some time. Once in a while it will drop to 1145 or go up to 1155 for a second or two.
I have never needed a really accurate tach on any motorcycle, I don't even use one to set the idle speed, I just set it to where it sounds and feels right. Fot syncing carbs, I either use the bikes tach, of if it doesn't have one, a cheap inductive type. As long as it is reasonably close that's all that matters to me. Consistency is mote important than accuracy.
I have never needed a really accurate tach on any motorcycle, I don't even use one to set the idle speed, I just set it to where it sounds and feels right. Fot syncing carbs, I either use the bikes tach, of if it doesn't have one, a cheap inductive type. As long as it is reasonably close that's all that matters to me. Consistency is mote important than accuracy.
