I was going to buy a used carb that has been jetted for a certain exhaust. Since the carbs were jetted can I use them on a quad with a stock exhaust. I was planning on no airbox lid with stock exhaust until I get enough money to buy a full exhaust system.

 

It will spit and sputter probably because its not jetted for a stock pipe. Use the stock jetting until you get the exhaust and then switch carbs.

 

You might be fine if you run no airlid and possibly an aftermarket filter. Why couldn't you just buy new factory jets and install them while the carbs are off? They're real easy to swap out once the carbs are off, and cheap - like $2 apiece and I think there's 4 total on the 660 = $8.