i have a 2001 stock FLHT. i put samson 3" miter cut slipons on it. part #DS202166.
I have popping on deceleration and too much gas coming out of the carb. it probably needs to be rejetted. What size kit should i use? Couldn't find the info anywhere.

 

What carb are you running?

 

You have a Twin Cam and you are in the Evo section but will be glad to help. Deaccel gurgle out the exhaust is a lean condition, the 01 CV carb usually comes with a 45 low jet and should be ok for just adding slip on's. The CV has a hidden air/fuel mixture screw, adjusting it takes care of issues like yours because it adds fuel in a throttle off and low speed situations. Attached a link if you are not familiar with the CV.

Fuel misting out the carb with the breather off can be common on a Harley if that is what you are referring to. If it is running out with the breather on then you have a problem, filling the exhaust with excess fuel and igniting it on decel which can happen but the above paragraph is more common. Fuel running out of the carb will need a new needle/seat for repair.

https://cv-performance.com/harley_mixture_screw_tuning