Why upjet with derestricted exhaust ?

I derestricted my basic exhaust and everyone says to increase jet. Could someone please explain why this needs to be done, just so I understand. And if I increase jet, do I need to increase carb air intake to balance the fuel / air mix? People seem to say to lighten rollers at the same time? Is the variator affected as well or is this just a separate , unconnected bit of tuning? Thanks

 

When you de-restrict the exhaust, the gases flow more freely in the engine and the increased gas flow causes the fuel mixture to run a little bit weaker as a result. Upping the jet size compensates for this and restores the mixture to normal. Add 4 to the jet size you have and that will be the size of the jet you need.

Lighter rollers in the variator will increase the acceleration a bit, as the belt will ride higher before the clutch engages.

 

Thank you, simply and clearly explained so even I understand.