I have an idea what's going on but thought I'd get input.

Now that we are into summer heat, when I throttle down to up or down shift, I'm getting a cough, almost like a back fire. Happens on darn near every shift and only when I throttle down.

Thanks for comments.

 

The Samson pipes don't help in this situation. You have decel popping, you can go into you 0 and 2% throttle position and add or subtract fuel to control the decel pop. (try 10 units or so to start) Do not change anything in those TP at 1000 rpm or less...that will effect your idle.

 

Thanks Doc!