What is this muffler?

[josh_oj]

Just picked up a 2003 YZ125 and it came with this muffler spare. What is it, is it better than the one fitted. Has bills racing expansion chamber fitted.

[Buddy L]

Depends on what you are after from your bike.

The first muffler looks like a stock item, longer, quiter, and giving the bike more back pressure to smooth out the power delivery.

The secound muffler, shorter in nature will give the bike more top end peak power as its alot more free flowing,, losing abit of the bottom end at the same time, most likely louder as well, depending on state if sound deading insulation.

But i could be wrong.

[B0000M]

the one on the bike looks stock to me,


the other looks suspiciously like a bills pipe - visually not very attractive imo

[noobi]

3rd vote for the muffler on the bike being stock.
The other doesnt even look like it will fit, the mount 'looks' like it wont line up if you compare it to the first muffler, and it again 'looks' like someone has put the second muffler together upside down, when you compare to the 1st, the mounts are on the top and the pipe that goes to the expansion chamber curves up, on the second pipe it curves down

[del-solider]

Yep 1st pipe is stock pipe

2nd pipe is a bills im pretty sure, got the same muffler on my 99 yz125. They can a bit loud, had mine tested at ardmore one day, freshly packed before the test and still got 100dB which is too loud for adrmore apprently :facepalm:

[josh_oj]

I remember the guy sold it to me said it was a FMF shorty muffler that had been repacked. I think maybe he has put it back together wrong which is why it doesnt look like it will fit?

[B0000M]

doesnt look like a shorty to me, unless someone has gone out of their way to paint the ends black and extensively polish out the stain that the FMF sticker leaves when you remove it / it falls off

[scott411]

the first one is standard, the second is a bills,

bills is the only place that i can remember that coated the singers,

and in 2003 they had a bit of a push in NZ with a new distributor

[josh_oj]

So would you leave the stock pipe on there or put the shorter one on?

[josh_oj]

bump bump bump

[scott411]

put one one ride it, put the other one on and ride it, see which one you think is the best,

louder is not always faster,