Topic: Do any of you run 130 or larger main jets on a stock motor?

[TwoTired]

I am not suggesting they are all wrong, but some may be..

 At 1100 ft with a header, pods or stock box, 811 or 836cc, and hotter cams , a few of us did not need 130S..

It depends on the carbs.

It depends on the pressure differential across the jet as to how much fluid flows through it.  Your jet orifice size changes are to compensate for the changes you make to the carb throat pressure.
"PODs" is NOT a specification.  There are several different kinds, they flow differently, and offer a different pressure differential across their respective filter membranes.

Trying to match a jet size to a generic POD specification is like saying two random motorcycles will use the same jet size. IMO

[754]

I was refferring to stock carbs on the 811s and 836s.

 I realize that, each bike can vary a bit, and jetting should be changed to suit plug out of that bike. What I am getting at is that if a lot of cammed bored motors dont need 130 or bigger why would a stock bore/cam motor need it at any elevation?

 I think a lot of bikes are overjetted, and when you ask the owner how/why they arrived at that size it is obvious it is not correct..

 Things like, I tried to check the main at full throttle, but couldnt pull over... well , it isnt on the main plug condition, if you didnt kill the motor and coast to a stop, is it?

 I find it hard to believe that you could only get 40 mpg (on a 750)  if jetted right, unless the breadbox is clogged..

[TwoTired]

I was refferring to stock carbs on the 811s and 836s.

 I realize that, each bike can vary a bit, and jetting should be changed to suit plug out of that bike. What I am getting at is that if a lot of cammed bored motors dont need 130 or bigger why would a stock bore/cam motor need it at any elevation?

 I think a lot of bikes are averjetted, and when you ask the owner how/why they arrived at that size it is obvious it is not correct..

 Things like, I tried to check the main at full throttle, but couldnt pull over... well , it isnt on the main plug condition, if you didnt kill the motor and coast to a stop, is it?

 I find it hard to believe that you could only get 40 mpg (on a 750)  if jetted right, unless the breadbox is clogged..

I agree.   
If you think about it...  Changing only the displacement, of an engine (same carbs, cam, induction, exhaust etc.)  Will make the intake vacuum go to deeper levels.  This increases the pressure differential between carb throat and outside atmosphere.  This higher differential forces more fuel through the same jet size.  An 811 or 836 ought to run richer if that is the only change done to the bike, and require smaller jets and adjustments to return the proper A/F ratio for the engine.

Yes, it also draws more air through the carb, too.  But, the increased velocity only makes the venturi more effective at dropping the pressure, and again more differential pressure forces more fuel to flow through the fuel jet.

[55fbomb]

i put in 130s because my plugs told me to.