In the good old days they just poured water into the carb.. all it will do is turn to steam and hopefully clean up some carbon... it doesn't fix anything. Plus the uneven distribution of the Siamese intake and distance from the 1 and 6 intakes from the 3 and 4 intakes means its not an even distribution.
If you think about it.. why would you want to clean your cylinders while it running where the junk can score the cylinders and damage a valve seat? Nothing you pour into an engine will fix it.
If you want to.. as noted, set a high idle and pour into the carb.. hope for the best.
There is a special tool for setting the valve lash... its a combo wrench and screwdrier... allows you to adjust the lash with one hand and hold the feeler with another. Its the easiest way to do it. Remember the motor MUST be running and normalized (oil at steady temp for 20 minutes).
