Hey Hey:
I wrote a novel about this when I was rebuilding mine for my 80 650.
OK, so we have really different carbs but the idea is the same....
In the years that our bikes were made, they had these tedious adjustment procedures called an "idle drop" that would allow dealers to set them up for the "leanest" condition possible, and then they were supposed to glue tamper-proof caps on them so that the owner couldn't mess with them.
If you want to read more about it, search for <idle drop> and you'll find my post.
Ideally, all the carbs will end up different, as there are variances between each carb due to mfg tolerances.
In the beginning, I tried hard to follow this "idle-drop" procedure. I bought another dwell tach because my old one wasn't working properly because of the SOHC "wasted spark", and the new one didn't really work perfectly either. I don't have the special right-angle screw driver for adjusting pilots, and I burn my hands a million times doing this -- and I eventually decided to ride my bike and see what happens....
The default setting for my bike was 2-1/8 turns out -- I figured honda must be joking as you'll go pie-eyed trying to keep track of an eighth of a turn. So I did 2 turns. It was very lean at this setting, exhibiting symptoms of leanness where at idle the plug was white, and if I turned off the choke before it was hot it wouldn't run. So I turned it out more until it seemed to start and warm up better, and I did the settings the same for every carb. After a few days, I noticed that it didn't idle well so I turned it back in a quarter turn, and so on. They seem to be OK, but not perfect. I didn't have the patience for the idle drop, but maybe you do.
My factory Honda manual says that your 1981 should start at 2-1/4 turns out. I suspect that this will be a bit lean like it was for my bike, but you need to try it yourself.
out
