Just installed a supertrapp IDS II exhaust and header pipe in my Honda 300ex yesterday. My question is why is the exhaust back-firing? Just added a couple a disc the exhaust back-fires and when I had 3,4,5,6,7,8,9,10,11 or the max 12 the exhaust still back-fires. I know I need to rejet to stop the back-firing which I plan to do next week. But I just don't understand why it is back-firing with the recommend 4-8 disc with no rejetting(or do I need to rejet no mattar how many disc you run). Am I putting the disc in wrong (Does the end cap or last close off disc that does at the end that in shape like a dome face inside looking like a dip or outside looking like a dome). Does this back-firing doing to hurt the atv if I go riding this weekend before I get a chance to rejet.

HELP!!!! I WANT TO RIDE THIS WEEKEND?

 

backfire through the tailpipe means your lean backfire through the carb means your rich anytime you change flow coming in or out of in engine you must check jetting

 

Thanks RedYam, for the comment I been sitting here hitting refresh buttom over and over wanting for some kind of help.

 

Chris0007,

If you are running lean, don't be riding it until the jetting is done. You will quickly melt a hole in the top of the piston and then the $$$$ will start to flow.

DJ

 

Thanks Dj, I guess I need to rejet this weekend?

 

Don't understand why its backfiring? Read the tech connection (advanced search (carb/jetting, all atvs)) on this website.

 

I have had hondas pop and snap when going downhill with suppertraps installed on my XR's, I had to go up one pilot jet size, raise the needle one and grab a main jet 10 numbers bigger to slove it. But I also had instaled a K&N filter with breether holes

 

please don't miss the obvious.. if the new exhaust has a leak at the head, causing air to enter the hot exhaust manifold, this can cause backfire also.

fresh air enters the hot manifold causing the unburned gasses (mostly on decelerating) to explode.

To reply to the prior posting of "backfiring thru the carb is caused by rich mixture" I had the opposite effect on my Bayou. It was too lean from the factory and would pop thru the intake/carb when cruising at slower RPM's. I richened the mixture via moving the needle up two notches and it fixed the problem.

great group here!.. keep those replys coming..

 

My 300EX, pops and cracks when letting off the gas...is this what yours is doing?

 

My Honda does that too, pops on decel. I have heard it's because it's a tad bit lean. Probably a factory setting..

I heard the fix was to richen the "idle mixture" screw 1/4 turn (backing out).

I haven't done that yet, but I will when I have the time.