I have a one peice pipe and mid box from a mid to late 70s sherpa 250. It has the square flange and retaining spring fitting, although the pipe has been welded to the flange. The mid box sounds rough as hell and I can hear things rattling about in there, so it's probably shot. For my M92, which would have had a three peice exhaust, I'm wondering if i can cut the mid box off and fit a new one, in the style of the original . Also wondering how the attachment would work. Does the pipe need to slot into the mid box, with the rubber coupling over the top, or does the rubber bridge a gap between the two? Does anyone make a mid box designed for replacing this part of a one peice unit?

Any advice would be much appreciated.

Cheers.

The rubber between the first part of the exhaust and the mid box only seals on my sherpa (1972). There is no gap between them. The first part is about 1-2" inside of the mid box. If you want to take a look at the inside of the mid box you can cut out a piece of it, maybe repair and repack it and put it together by using clinches and a piece of sheet metal. Of course you can weld it if you want to but I didn't have any welding skills :-). I described in the Montesa forum how I did it with the clinches.

http://s8b.directupload.net/file/d/1835/mnz6ymj5_jpg.htm

bye, Felix

Edited June 26, 200917 yr by FSB

Here's what I did.

Sammy Miller exhaust

Dave

did you have to cut the old expansion chamber off or did you have seperates to start with? If you did cut it were you left with enough pipe to fit inside the new middle box?

Thanks for the help.

hoodie.

Dave

did you have to cut the old expansion chamber off or did you have seperates to start with? If you did cut it were you left with enough pipe to fit inside the new middle box?

Thanks for the help.

hoodie.

Here's what it looked like originally. It was quite bad. And quite loud.

Once I got it back together I cut the header pipe from the muffler and added the rubber joint. This made it a bit easier to remove the exhaust... And I added a $10 JC Whitney muffler on the end. Which made it a little better but still not ideal.

I want to replace the header pipe at some point. This is an early M92 so I think it was was chrome with a rubber joint.