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Bultaco 91 Exhaust

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hi this is me first post just bought a bultaco sherpa 91 model looking for a silencer to fit bought the triangle silencer

but diameter too small plus sits too high to reach pipe, only looking at silencer as want to put day mot on her, any ideas please

post-18178-0-60362500-1364117904_thumb.jpg

Looks like the mid box is the new Miller products type, so you could try repacking it to quieten it down. Most MOT stations that are happy to issue day light tickets look quite favourably on competition bikes, so take it to the tester, start it up and ask if its acceptable!

None of the original type end sections ever seem to fit well, I would just clamp a straight tail pipe on if it's loud for the MOT then remove it when passed!!!

Your frame, is it a Miller high boy or a modified early M91 frame ?

Regards,

No balance.

  • Author

hi is the miller pipe classed as a silencer just seen one on there website under the section silencers very similar to mine if so then repack maybe best option is the frame miller high boy or modded m91 frame not sure no dodgy welding anywhere this is the first twinshock i ever got all i know is model 91 matching engine and frame numbers 1973 year, is the miller high boy frame suppose to be better than the standard anyway, lots to learn, thanks for replys.

Hi, yes I would say the Miller mid section is a form of silencer, doesn't have to have E number or any of that old rubbish, as for your frame, the number on the head stock would start SM so it's probably a modified M91 frame, looks very nicely done what I can see of it. I think the Miller frames were lighter/stronger than the standard Bultaco frames and bronze welded, with a nickel or chrome finish. NB.

Hi. I have the same SM mid pipe on my M49 and I fitted the triangular silencer. I just used a piece of heater pipe hose to reduce the outlet of the mid pipe to the triangular silencer and welded a lug on the Millar mid pipe to hook the spring on to, and it made a considerable difference, it was quite noisey with just the SM pipe and didn't seem to run well,(Something to do with lack of back pressure I presumed). Hope this helps.

  • 2 weeks later...

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