In peering at my mk3 wondering why one of the exhaust nuts vibrated loose at the weekend, I noticed an odd thing. Neither exhaust pipe exits the port / nut concentrically; that is to say they are offset to one side. As you look at the front of the bike, both exhausts are offset to the left. Is this likely to be shoddy pipes, shoddy assembly, or are they all like that? It may be worth pointing out that it has pattern Campbell's cigar silencers, rather than black-caps.
So, here's a funny thing
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Rohan said:
Yes, the MkIII pipe-to-head spherical joints can acommodate a certain amount of pipe misalignment, however under the circumstances, personally, I think I would want to check the pipes are the 'flared-end' MkIII type and the correct MkIII spherical seatings and collets are present and assembled correctly.
Rohan said:
But it is possible for the head steady to pull the engine slightly off vertical if not set up correctly (and of course, the centreline of the Commando engine/cylinders/cradle etc. is offset approximately 1/8" - 3/16" left of the frame centreline).
My Mk3 is also (can) look like photos.. I found that loosening off the flange nut and muffler clamp the pipe could be centralised closer for appearance sake, but where the pipes "flow" under your feet there can be a significant distance from pipe to frame and each side unequal..
I noticed this once when i tried to "tuck" header pipes in close to the frame and got the above picture.... I settled for flange nut/conical end alignment over header pipe visual symentry... I bet if you had several pipes for either side you would find they would all "fit" different.. It a Norton and some quirks you have to live with
I noticed this once when i tried to "tuck" header pipes in close to the frame and got the above picture.... I settled for flange nut/conical end alignment over header pipe visual symentry... I bet if you had several pipes for either side you would find they would all "fit" different.. It a Norton and some quirks you have to live with
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Don't be getting yerself all stressed out over such a thingy. Betcha the pipe landings were cut that way and the flanges to the crush rings welded that way. Mk111 was the one most likely to run too tight to the motor so someone had a smart idea at the WORKS one aft. after teabreak or union meeting ,once they realized amalgamation announcement after lockout strike time drinking teas and pondering and twiddling thumbs. Only way to really ascertain is to pull exhaust and study pipes,threads and ports landing home. :|
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Torontonian said:
Doesn't apply to MkIII (the standard MkIII pipes do not have welded flanges, and no crush washers are used).
Torontonian said:
The pipes are clearly non-standard MkIII items (as they don't have the balance pipe).
Simply loosening the exhaust rings and realigning the pipes may cure the problem, although it could transfer the misalignment elsewhere if the pipes are not the correct shape.
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As noted - those are 750 pipes so who knows how they align compared to the correct 850 pipes. You can't complain about alignment if you are using the wrong pipes - as most 850's nowadays are. 
I just acquired a NOS set of 850 (balanced) pipes but I don't have the collets for them. When I'm in the US over Xmas I'm going to have the collets delivered to where I'll be and try the 850 pipes on the bike when I come back to Mexico. I'm looking for a huge power increase!
OK, in reality I'm just hoping for a tiny one!
I just acquired a NOS set of 850 (balanced) pipes but I don't have the collets for them. When I'm in the US over Xmas I'm going to have the collets delivered to where I'll be and try the 850 pipes on the bike when I come back to Mexico. I'm looking for a huge power increase!
OK, in reality I'm just hoping for a tiny one!
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mike996 said:
Non-balanced pipes are (or at least were) available for the 850 MkIII (with the correct flared ends) and fitting "750" pipes to any other (pre-MkIII) 850 shouldn't result in any alignment problems if the correct parts are used (exhaust mounting brackets etc.). How well the pipes fit tends to depend on who made them.
http://shop.triumphtwinspares.co.uk/nor ... -303-p.asp
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Correct ,no crossover pipe means 750 style. Not MK111 originals at all. Unscrew nuts and get to the bottom of things ,just takes a few minutes. Once had a set of 750 type back when that splayed outwards quite a bit ,my newer ones do not. The shop Bloke cared back when. Sometimes they grabbed a pair off the shelves and if they didn't fit without touching the Bloke would just put 'em back and try another set !
L.A.B. is correct, as usual.Most 750 headers do not fit the MK111 correctly,as the larger primary interferes with proper alignment. Notice I said MOST. You will find different fitments with different manufacturers, and the only reason (as stated before on this forum) for the collets and such was to facilitate removal of the headers with the balance pipe, thus the flared ends vs flat surface. its a crap shoot . trial and error, sad to say
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With the nut cracked a turn loose , can you shuffle / lever ( carefully ) the pipes about in the nut , as in shift the gap ? ?
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