V4 Strong Exhaust Fumes From Akra Full System

Discussion in 'Multistrada' started by Muppet, Mar 12, 2026 at 10:47 AM.

  1. I had a dealer fit the Akrapovic system to my 2024 V4S together with the upmap and ever since I've got very strong exhaust fume smells. This wasn't present before. I was expecting some given the absence of the cat but everything really stinks, clothes, boots, luggage, everything. I can't find any obvious leaks from the system. Is this really to be expected? I've not picked up on anyone ever mentioning this before. Sounds daft but it's really annoying me! If there's nothing else I need to be checking then it's going back in to the workshop..
     
  2. the bike i test road had a full ackra system and it did have a octane smell but in a good way
    I bought a rally v4 multi with standard exhaust and it has no odours...........except me !

    so your situation would seem normal
     
  3. Run a 1260 with no Cat and on initial start up it does smell like a motorbike should and expect with more fuel on a cold engine..
    Once warmed up its not really an issue tbh.. might be worth getting your bike looked at/mapped properly/ check what is really happening with the fuelling by an expert.
     
  4. Stinks when out and about or in general? Could be they knocked a breather tube off and forgot to plug it up again, causing fuel vapours to pour out whilst sat up, stinking (or smelling nice to some) of fuel.

    Else yea, without a cat and a 'full' (OEM headers with the full kits) setup, you'll obviously have unburnt fuel come through a lot more than previously. My 1260 is a bit whiffy and as @Rich4 said, it's normal. As once up to temp, most of the fuel will be burnt up from hotter running temperatures. Physics yo.

    I've removed my EVAP unit as well, which makes it even worse!
     
    • Like Like x 1
  5. @freshage
    What's the advantage of removing the Evap unit?.. just unnecessary enviro clutter, weight, euro regulatory BS? Or cosmetic reasons.
     
  6. I removed mine to make way for a Denali Soundbomb…something which is much more useful :)
     
    • Like Like x 1
  7. Enviro clutter. However, many (mostly Americans) seem to have problems with the evap canister because they fill their tanks to the brim so it’s almost overflowing. It then does overflow as it gets hot and expands and as they go around a corner and it sloshes about and it fills their evap canister with petrol rather than fumes which then causes issues with the sensor the evap canister. Why they would fill it so full is beyond me but then most things Americans do is beyond my understanding ie fecking stupid.
     
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