My exhaust exploded

[evan402]

Haha well this was just crazy and i have no idea what caused it. I recently removed the choke on my carb so as long as i had it apart i went down in jet size to 165 from 170 because it seemed to run a tad rich. It seemed to be running fine but backfired a couple times and one of the times this happened. So was i running to lean? Rode it back to the truck after this and it had no ill affects. pretty crazy tho.

http://i379.photobucket.com/albums/oo236/trullitaken5/iphonepics9-14-10202.jpg

[01boneless]

omg what type of exaust you going to add now lol :)

[evan402]

hmf slip on. im wondering if fuel puddled in the slip on and ignited?? idk still kinda stumps me.

[bkb88]

I have a White Bros E-Series can that had the core go bad that I would sell you for cheap. Send me a PM for pics if you're interested!

[evan402]

Nah thanks i love my hmf on my predator so thats what im looking for-unless i can talk the wife into letting me get a sparks full system!

[kbnorth99]

I'm dying to here how this happened. Guess I should be careful jetting my carb next week. I have pretty much the same pipe.

[CJM]

Friend of mine had this happen, was due to the packing in the muffler being pretty much gone. He kept riding on it for a few more rides and ended up with a huge hole.

[evan402]

Hmm thats actually what my brother thought happened. I never repacked the exhaust since i bought the quad last sept. I never loved the sound of it so it wasn't a huge priority. That would bring me to a new question then. How do you know when its time for a repack?

[B.C.#11TRX400EX]

wat does packing do? and if u buy a new exhaust do u have to pack it? can u just buy it and put it on?

[fish22]

Originally posted by B.C.#11TRX400EX
wat does packing do? and if u buy a new exhaust do u have to pack it? can u just buy it and put it on?

packing is the absorbent material inside the muffler. new ones come with it in there, but after a while the packing burns off and has to be repacked.

[CJM]

Its nothing more than fiberglass insulation. Heck last one I packed I used insulation from home depot.

[crownandmonster]

FMF recommends repacking every 40 hrs (which seems to early to me), but if you put a lot of hours on your machine repacking once a year is probably a good idea. When you do repack don't use fiberglass insulation, it doesn't last. Wrap steel wool tighly around your core and then wrap some high temp tape around the steel wool to keep it snug against the core. The Steel wool will last much longer and has no ill effects on sound quality.

[slightlybent47]

Looks more like metal fatigue to me. How old is the pipe? It also looks like the tire has been rubbing the pipe. It also looks like that’s where most of the heat is located and that would break down the metal-aluminum over time. Could also be the packing came apart and got wedged in the pipe before it was blown out. That might cause an increase in presser momentarily and with a weakened pipe it could blow the side out. Or where ever the weak point is. Heat cycles will weaken metal over time.
It’s also one of the things that the packing does is insolate the can from the heat so it extends the life of the muffler.

In other words it can and will burn out over time just like the muffler in your car.

[evan402]

no clue how old the pipe is. it never had any contact with the tire- i know that for sure. the opposite side of the muffler is blown out too in exact same spot. I believe it has something to do with the packing. Either way i am now in the market for a slip on!

[kbnorth99]

I know you said you wanted an HMF. There is an HMF for sale cheap. If you can weld aluminum. There's a cracked bracket.

http://www.exriders.com/vbb/showthread.php?s=&threadid=469014

[evan402]

lol yeah i want that one. can you hold it til friday? IF so ill take it!

[kbnorth99]

Originally posted by evan402
lol yeah i want that one. can you hold it til friday? IF so ill take it!

FYI.... It's not mine. I just saw the thread.

[evan402]

doh!