Got an FMF MEGAMAX muffler for my 01 scrambler 500. Nice power gain however it pops upon deacceleration. My wife has an 03 and hers does not pop at all.I remove 3 discs and it does pop a little less. My wifes has all 9 discs in and it works fine.What type of jetting needs to be done . Thanks

 

you can put in a stage one dynojet kit.check your exaust pipe where the spring ataches the to header pipes together for weak springs causing exaust leak.this will cause the popping you are talking about sometimes.also check the rest of the exaust for leaks and holes.

 

yes weak springs, or bad donut seal between the sections of pipe. popping during deacceleration usually indicates a lean condition. mine did this when i had a bad donut at the first pipe joint,, causing a substantial leak.

i decided to jet up my pilot jet when this was happening to me,.. and popping went away. stock is #40 and i went to a #42.5

X

 

Thanks for the info. You have some really cool stuff on your scrambler. The winch is awesome. How did you do that.Trade secret? What kind of rear rack is that. My quad doesn't pop with the stock exhaust.My wife's quad was already modded before we got it. I was a die hard cr500 rider till I got older and my racing days are done. I upgraded my ol lady quad from an 86 300 2 wheel drive bayou to a scrambler I bought off of ebay.After riding hers I am now hooked.Hers will out run mine. Now mine with the airbox mod and muffler feels stronger but the popping is annoying and did not want to burn out a valve.thanks again.

 

also, those fmf mufflers are supposed to work with stock jetting.

you can richen yours up a bit by lowering the needle clip a notch or two. if that dont work, go up a size also on your main jet.