Scout Balance Factor

[JTR249]

That's what I saw, Cotten. There was a man ("Ridge Roamer") who once made a youtube video about how to start a 1946 Chief, my favorite, and I think that's what I saw him mention.
He had his set up for left hand idle adjustment in the video and demonstrated other basic things of course.
I, in turn, know next to nothing about Chiefs and Sport Scouts, though some day will.
VirtualIndian.org is still a lasting resource. That was my first awareness of Jim Mosher's work.
Thanks again.
-JR

[T. Cotten]

They were all that way, JR!

And harleys too until the auto-advance (or is it really an auto-retard?)

But harleys didn't have to retard to get in gear, usually...

....Cotten
PS: The absolute silliest balancing theory extreme was when S&S promoted shaving down the female rod top to match the male.

Good thing these things are so forgiving.

PPS: The VI webmag stalled out, but the mailing list is still quite active: https://groups.io/g/VirtualIndian

[T. Cotten]

....I often wondered if Indian even balanced every motor.This would very time consuming and maybe not needed if all components are the same.How far off can a run of flywheels be from each other?...

Funny how many flywheels had no holes at all, Tom!

And those that did, were so symmetrical and perpendicular to the crank/pin axis that you know they weren't treating each wheel individually.

Modern dynamic balancing lets you poke a hole in the mass where its needed most. Determining that spot statically takes more than just patience, but if you listen to the hardware, it will tell you.

...Also how was original factor determined?Most likely trial and error,racing results etc...

Perhaps a factory built multiple test machines identical, except for factor, right?

Sorry, but we are back to hearsay, consensus, and thin air.

The only thing that we know is that the Founders had true genius. If we could ask them, they would say it is obvious.

....Cotten

[Peter Cooke]

Why is only the weight of only1 piston & rings used when balancing a v twin?

[T. Cotten]

"Why?" begs a "because" answer, Peter...

And its because it works! (The real mystery is "how" the Founders arrived at such a simple and practical technique.)

Motor balancing is making the countermass equal a fraction of the reciprocating mass. How brilliant that they used the actual hardware to be its own balance scale, eliminating math errors and multiple assemblies.

The useable factors for v-twins range from about one-half to two-thirds of the real reciprocating mass. Once you know your rod tops, you can calculate your existing factor, and then decide if you want to change it. (One piston assembly on a Chief gives a factor of ~64%, allegedly higher than harleys because of a wider angle between cylinders.)

....Cotten