My $0.02 on Manometer Settings

[Ray from Indiana]

The "airhead manometer" measures the difference in pressure at the carb venturies. Any U tube manometer measures the difference in pressure at its terminals plus the pressure difference due to the elevation of the terminals and the head of lighter fluid ( air in our case ) above the heavier measurement fluid ( trans oil or other in our case ). Assuming the terminals are at the same elevation (the carbs are at the same height for all practical purposes), the head difference above the heavier measurement fluid cancels out whether it is alcohol, another lighter oil, or air because it is difference in head that we are interested in. If the terminals are at the same elevation neither the diameter or length of tubing or volume change the reading of STATIC head difference between the two terminals!

Remember I said STATIC head difference. Now if we want to blip the throttle and watch the depression of one side of the manometer or other there would be a lag time on the leg that has either a longer leg or larger diameter before a static reading is justified...but if allowed to adjust for the additional air removal the reading would be the same as if both legs were equal diameter or length.

Any airhead that wants the tubbing to be a little longer on one side for convenience can do so with confidence that the readings will be in the ballpark and because there is a lot of imprecision in reading the difference one shouldn't get hung up junk science - just set it close to balance as you can and ride......OCD on physics and false precision will not get you out of the garage.

[r90s]

"junk science"....

You showed yourself there.

What is your science background, Ray?

Jon-Lars
Beverly, WA