OzVMX Forum

Clubroom => Tech Talk => Topic started by: Graeme M on July 11, 2009, 11:19:16 am

Title: Muffler repacking question - modern bike
Post by: Graeme M on July 11, 2009, 11:19:16 am
Hoping someone has experience with repacking Pro Circuit 'Shorty' mufflers. I want to repack the one on my 05 YZ125 and it seems simple, unscrew the three screws at the inlet end and the inlet pipe and cap should just come out with the core. But it will not come out. Is there a trick to it, or do I need to get really forceful? I am always wary of trying to force things...
Title: Re: Muffler repacking question - modern bike
Post by: VMX247 on July 11, 2009, 11:53:31 am
No tricks..Yep it is a hard job,it maybe all gumbed up .Try some heat.
The whole lot (core)will come out when it does..  8)
Good luck.
cheers S&A WA
Title: Re: Muffler repacking question - modern bike
Post by: TT5 Matt on July 11, 2009, 01:19:59 pm
hi Graeme
put it back on the bike and take it for a good hard ride to get the gummed up oil holding it together to soften  failing that soak it in some old waste petrol for a few days


TT5 Matt
Title: Re: Muffler repacking question - modern bike
Post by: Graeme M on July 11, 2009, 05:49:54 pm
You'd think it'd be that easy but nope. It comes out about 3 mm and then stops. There is a solid metallic click at that point so there is definitely some mechanical reason it won't disassemble. I can't believe I have to grind the rivets off as well...

It's one of these, I'd assumed only the small bolts at the inlet end had to come out.
(http://www.mta-la.com/Portals/0/images/Exhaust/procircuit/pc-r304silencer-full.jpg)
Title: Re: Muffler repacking question - modern bike
Post by: VMX247 on July 11, 2009, 07:21:51 pm
You have to take the outlet end off.
On our modern 4strokes we have to drill the rivets out.
The first time we thought it couldn't be right.  :-\
 but I rang a mate and he said "drill the rivets son"  ;D
cheers Steven, Alison and Ben. ;D
Title: Re: Muffler repacking question - modern bike
Post by: Freakshow on July 15, 2009, 03:31:59 pm
the yamaha stock kit come with 4 or so rivett and the wool in the bag so you must have to drill them out somewhere too.

if as per that pic the tial tip is attatched to the inner, then there is no way that angle will get through the cap.
Title: Re: Muffler repacking question - modern bike
Post by: Graeme M on July 15, 2009, 05:39:36 pm
I got it sussed in the end. You do only remove the three hex head screws and the pipe and core come out as one through the front. My problem was that the perforated core extends through a flange in the end cap and it had a slight crease which meant the core was catching on that flange. Earlier I had tried to free the whole shebang with a drift and a few taps against the core but it never occurred to me that I'd bent it. So a tweak with a flat blade and out she came... I'm just a dummy I guess  ;D