[Kiwi]

A while back I recall seeing a post talking about how to modify a stock CRF150F muffler so that it breathes better ... and makes for better power. But alas, I can no longer find the post.

I remember something about taking out an internal plate and drilling some holes in it. However, my questions are:

1. What is the plate
2. How many holes should be drilled
3. What size holes
4. How much louder does it make the bike
5. Is the time/effort worth it ... does it really improve power
6. Is the muffler mod enough to warrant re-jetting