[jacklavallet]

I don't understand... why do I have to adjust the carb when I replace the stock exhaust system? I assume it's because I open the engine up with less back pressure, resulting in more available power, but then the "stock" carb settings make the engine run lean. I've seen references to something called the "scar" adjustments. Is that just "one way" to make the adjustments? Thanks for any help.

 

[Charlie D]

yes the scar mod is resetting the carb for the additions you add such as pipes and airbox.

with just a set of pipes you would need to open the pilot a little to balance out the air to fuel ratio, if you then add a free flowing air box you would need to shim the needle which allows the main jet to be active just a bit sooner.

 

[xdanman]

yes the scar mod is resetting the carb for the additions you add such as pipes and airbox.

with just a set of pipes you would need to open the pilot a little to balance out the air to fuel ratio, if you then add a free flowing air box you would need to shim the needle which allows the main jet to be active just a bit sooner.

Thats right, you only have to shim if you change both. If you just change pipes, or breather alone, you can only get as much out of an engine that you put.If that makes any sense. Just an a/f screw adlustment will do.
I think I confused myself.