Stupid question about aftermarket exhaust muffler

Discussion in 'Technical' started by Changnoi1, Apr 30, 2014.

  1. I installed my Leo Vince slip-on muffler (that I bought for my Honda CB500F) on my Kawasaki Z250. And although I love the look and the sound (not sure what the rest of the mubaan thinks of it) but I have the feeling that I did lose power in the low-end.

    Am I crazy or could I be right? This morning I did put back the stock muffler and my feelings seem to be confirmed. Later today I will try the Leo Vince muffler again on the same stretch of road and see if I really notice a difference or if it is just a feeling.
  2. You probably need to adjust your fueling for the new exhaust.
  3. You mean like remapping the ECU? I did read that on older models of the Ninja 250 people would rejet the carb.

    When refitting it I also saw that the slip-on was actually not good tightened to the header. I did put another clamp on it and tightened better.
  4. Going from stock exhaust on a 250cc bike to an aftermarket slip on designed for a 500cc bike you have surely lost a LOT of back pressure. You will need to remap your fueling to compensate. Personally I'm a big fan of Dynojet's PowerCommander Fuel Injection Controller, but there are plenty of other options. Read more here:
  5. Thanks for the info, still considering if I want to go that route ... just for a better looking & lighter muffler and a bit more sound (the latter is the only thing I appreciate safety-wise). But....

    The header of the CB500F was I think 45mm, the header of the Z250 is I believe 38mm. Although I was told that the same muffler is sold for the Z250 and the CB500F I start to have my doubts about that.
  6. Have you tried it with the dB killer insert. CB500 comes with a 25mm outlet. Exhaust for Ninja also comes with 25mm outlet.

    Might give you enough back pressure.
  7. Yes, tried without dB killer first but now using the dB killer. With dB killers feels better indeed.

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