Having just spoken to birckett motorsports about a knock on my ty250mono it now apears it could be down to a blocked middle box.I wonded how do you go about cutting it open and has anyone done this and the knock and had good results. cheers peter.

i am just in the middle of doing my mid box i used a 1mm cutting disc in my angle grinder cut the back side of the mid box.tok out the the black oily packing repacked the box and cut out a new bit of sheet steel to cover the bit i have cut out and then i used a TIG welder and welded the cover back on.you could use a MIG welder but try to keep away from a ARC welder as its a bit fearce and will burn thro the thin sheet metal and burn the packing a bit. as you say you were taking to birckett motorsports about a knock and they said it may be a blocked mid box i would not have said that was the problem as when you open the mid box there is only a tube with 2mm hole around it going thro and the backing i took out of my box was very thick and had gone hard thro the years of use and none of that would clogg the box up as it s to thick to get thro the holes and if some very very small parts got in to the mid box they would have been blown thro and would have come out the end of the silencer hope this helps

Just in the process of doing mine. to get at it properly I cut the front section off where it meets the middle box then I cut the back off the middel box.

Burned out the front section and the now open mid box, ripped out all the old packing before repacking and welding up........I'm using mig on mine, set it really low and it's ok + I've done all my cuts on the back of the mid box so you can't see when it's finished.

I used a 4.5" grinder with a small thin cutting disc to do the butcher work.

I thought about all this effort and then despite my natural tightness went out and bought one of the stainless systems that have been produced.

Quality and fit is first class and it certainly runs smoother and quiter and looks pretty trick.

Easy option I'm afraid won this time.

IS the new exhaust the ones on ebay ! If not were did you get yours from and how much did you pay and what was the fit like .cheers peter

Yes the one on ebay from Promonty

Fits perfect

I must admit I did nearly buy one myself, were they about

Edited June 7, 201016 yr by Marky G

I've got a promonty stainless on one of my ty's - runs much better - nice ands smooth - sounds good too.

Ive now just repacked my middle box and waiting for my mate to weld it up if it stops the clunk ar defination! then i will get a new pro monty one . If not having had the barral and head off and carnt find whats making it clunk i think the ty will end up in the skip.

I think if I was going to the effort and expense of creating a replacement in stainless I would be prepared to sacrifice absolute authenticity to get rid of that hellish ugly seam on the pipe.