My 1300 vtx 2005 backfires through exhaust when I let off on throttle. Thing is, it has no HP loss. Still runs fast as ever. This bike has been jetted and hard chrome pipes. Just a big bang sometimes not all the time when I let off throttle.

Get the fueling set up on a rolling road. Honda set the fuelling to suit the Emissions and the Exhaust they fitted.An after market exhaust will usually have less backpressure and need a set up. When you say backfire, do you mean a great big bang or just a little popping sound from the exhaust? If it is the latter, it isn't a massive problem but a set up will cure it. A Big Bang could be a cause for concern as it means the ignition is taking place when the Exhaust valve is open and firing in the exhaust itself. This will give a drop in performance and may cause the engine and exhaust to fail.

make sure there isnt any thing in the air box or exhaust little critters like to nest in them

May be running too lean or too rich. Check the color of your plugs, black dry and sooty means they are rich, white with blisters lean.

great news you can only win with this. i bet if you pull a spark plug and look at it, it will be white or close to it. if so your motor is lean, it's not get the right amount of gas. when you put pipes on a bike it lets more air flow and you need to jet your carb. you local bike shop can help you get a jet kit and handle the install if needed. when done right you get more performance out of it. while you are look into jets get a high flow air filter or look into a hyper charger they come a jet kit, k&n air filter and the air scoop price isn't bad rsports.com/wps/Honda_OEM/HondaMC.asp?Type=13&A=474&B=25

Check the wiring to the spark plugs and replace if necessary.If that does not solve then go one step further backwards towards cdi etc...

Check to see if you have an exhaust leak at the rear cylinder. A slightly leaking exhaust gasket can cause this.

If you have used Dyno jet kit I have had a kit come through with smaller main jets than the stock ones causing it to run way to lean.

Hi TJ,
There are a lot things tht may cause backfiring.
It could be due to the timing being incorrect.
It can also be due to the gas having water in it.
When did you start facing this problem?,suddenly, or after some reapirs or was the bike stored for a longtime ?