New powerbomb header/KX muffler- Popping on decel

[Bat24]

1st post but first thank you all for your helpful info. I've learned so much from this site.

Question- Put on a new powerbomb header and KX muffler. What a difference but lotta pop now on decel. I've read that re-jetting is not the answer as it has more to do with fuel mixture. True or Not True? Any ideas on how to fix or decrease it? Does it harm the bike or is it just annoying. Thanks in advance.

Bat

[bmeyer2017]

If your running stock jetting with those you'll blow the motor quick. You need at least a 165 main jet in there.

[bob_e95482]

I am also running a Powerbomb header with a KX450F silencer. I have also rejetted, and removed the airbox lid and AIS. My bike runs great.

[Rome06379]

You NEED to re-jet or ruin your engine. More flow= more gas needed! Get the JD kit. It's pretty easy and had all the info you need to get her running perfect:thumbsup:

[Bat24]

I just got a reply of the guy I bought bike from. He had it jetted at "45 pilot, 165 main, "red" needle clip 4th slot from the top".

You think it is necessary to jet again? Bike runs great just more popping. Haven't messed with the fuel screw yet.

[Johns08KLX450R]

I have a 50 pilot in mine with screw 1.5 turns out

[92db]

Symptom you describe is typical of a muffler that needs to be repacked.

[klx450junkie]

Get the R&D flex jet fuel screw it cured my decel popping.

[KLX450-DIRK]

Is the AIS removed? If not, it will pop no matter what you do.

[Rome06379]

:thumbsup:That jetting should be good. Just make sure you have a tight seal between pipe/header/exhaust port. Any leak will cause popping?

[Bat24]

Thanks all, problem solved by adjusting the fuel screw. Still pops a little but not much. Feel like I have a new bike.

[KLX450-DIRK]

I'll ask again...cuz i'm curious...

Is the AIS removed? If not, it will pop no matter what you do.

[Bat24]

Sorry, thought u were making a statement with your question. Yes, AIS is removed and all usual mods are done.

[KLX450-DIRK]

Sorry, thought u were making a statement with your question. Yes, AIS is removed and all usual mods are done.

Thanks! Curiosity appeased!

[jimmyh]

Second the R&D flex jet fuel screw. For those of us who ride with elevation changes and quick 1/4 to 1/2 turn makes a big difference in performance and decel pop.

[Bat24]

Finally got out and really tested the new set up at Hollister Hills. Evaluation-

If you have not changed out your exhaust system for something lighter and less restrictive then you don't know what the KLX is capable of.

Lighter, quicker, pulls harder,

Overall cost of extras- $250 header/muffler used on ebay

120 Turn Tech battery .9 pounds

35 AIS removal