I received my Speedwerx slip on muffler yesterday. The instructions say to open the hole next to the needle opening out to 1/8". I have a couple of questions about doing this.

1. Why do I need to do this? More air? More fuel?
2. If I do this and then go back to my stock muffler, will that cause me any problems?
3. If I want to add a dynojet kit later will this 1/8" hole affect it's installation or performance?

Thanks in advance for any help. I've never really messed with carbs much.

 

i would call the manufacture,let us know what they say,maybe its a good idea...