Flow meter tunning

[hederjr]

I noticed alot of people use a flow meter to set the carb before a race. I have a couple questions about this.
1. Why use propane?
2. Why set it at 40" of w.c. before setting the carb?

[Ron Olson]

1. Because it's fairly cheap and easy to get.
2. For a basis number for adjusting everything.

[hederjr]

So does it really matter if you do it at 40" or say 20" ?

[Ron Olson]

I really don't know, you've pretty much gotten all that I know about them above. I'd like to get myself one eventually as once you know how to use one they can save you from a lot of DNF's and DNS's.

[hederjr]

They are very simple to use. I watched some racers use them. ITs very accurate way to set the carb no matter what the weather condition. I asked the racers the same questions and really did not get the answer I was looking for. I plan on making one but want to know more about the why before i do. Most important why 40". The racers said it was kinda a standard.