Since you're using a 125 I'm assuming an early-style carb.
XT350's use a 125 main and #42 pilot in their main (primary) carb. Same basic carb.
The jets used in the secondary carb won't swap.
XT350's use a 125 main and #42 pilot in their main (primary) carb. Same basic carb.
The jets used in the secondary carb won't swap.