New expansion chamber + muffler causing excessive low speed bogging. How to tune?

[Street Ryderz]

As you can see in the above diagram the main is only responcable for around 25% of the throttle range.

 

[gary55]

As you can see in the above diagram the main is only responcable for around 25% of the throttle range.

I might be off on the read of the chart, but I think what it's saying and what makes sense to me is 3/4 to full is all jet, from around 1/2 to 3/4 is mostly jet with some needle influence, from around 1/4 to 1/2 is mostly needle with some jet influence, and below 1/4 is pretty much needle influence. With the NT even more so as their is really no idle circuit other than the needle. Is my thinkin right on this?

 

[gary55]

I just found a post that said the jet controls 80% to 100% throttle while the c-clip controls everything below that. Is this is true, then should I be adjusting just the c-clip?

You can start with the c clip, But generally adding a good expansion chamber is going to change the dynamics of what is happening with your scavenging and the return sonic pulse to require rejetting.