big jet in vertical pot or horizontal ?
Base setting again I have a 135 And a 140 Main, the carbs dont belong to this bike and I dont know whi ch pot gets the big jet ?

I was told that with bevels the rear runs hotter so it gets the bigger main, but with belts which rotate the opposite way the front gets hotter so the front gets the bigger main. ?????? (but it sticks out in the cool air?)
This is a question I have wondered about for a long time.
I was told that on a belt the front cyl gets the first fire to push the crank and then the rear to keep it rotating, the front has the most work to do,opposite to a bevel.

I used the same jets in both carbs, but mine is a road bike.
I'd like to hear what seroius racers have to say about this.

graeme

I've always run the same jetting horiz/vert. Never noticed enough of a difference between them to run the vert richer. This is on bevels and belts.Maybe I'm not WOT long enough?

The many variations of F1s run a larger jet on the V (rear) cylinder on both the 36 and 40mm carbs and, likely, many of the Pantah engines with carbs do. Shows up in the manuals, and in many books. The rear runs hotter because it is blocked from the wind by the front cylinder; cannot risk letting it be lean. MikeV

+ 1

Thanks again, I have the old girl running now!