250ex Exhaust & Backfiring

[wrk24wheel]

Has anyone had experience with the HMF exhaust? They claim a 2HP gain over stock. I have seen slip ons that claim more than that. How is the FMF exahust and can you really tell a difference. Please give me some recommendations for this. I am really just trying to help out the bottom end, it just seems like a dog off the line.

I also did the airbox mods and now the quad is backfiring on decel. I can not find a pilot air jet, is there one in this carb?

[cals400ex]

there will be a pilot jet. you could try turning out the fuel skrew first though, well i assume its a fuel skrew on that carb. it is probally a bronze skrew on the very bottom of the carb. if not, you may want to get a larger pilot. with airbox mods or exhaust and with it being colder outside, there is a good chance you will need to move your needle up one position.