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New Muffler - Shooting Flames

Discussion in 'Technical and Troubleshooting Torque' started by icgreen, Aug 16, 2007.

  1. Hello...I'm a first time poster but long time reader of this wonderful site!!! I'm quite new to the biking world only recently getting my license and a new Hyosung GT650R LAMS restricted bike. I was hoping someone could offer advice on a technical issue that I may/may not be having...Today, I had a brand new Micron Carbon Fibre Muffler fitted to the bike. It sounds absolutely beautiful however I am a little concerend becuase when I de-accellerate at times the muffler pops/backfires and shoots out bright blue flames...I have been told by the company that fitted the muffler that this is quite normal for my bike due to the fact that it is restricted however I was hoping I could get a second opinion. The Muffler is a straight bolt-on type and there have been no other modifications to the bike at all. As I said earlier, it sounds great and does a good job of keeping cars well away from me but not so sure if this is normal. Any help/advice would be greatly appreciated on this topic...Thanks.

  2. dont worry bout the popping and the flames. those are cool. it happens on my gt250r and it hasnt stuffed up the bike.
  3. Could get the carbs tuned.
  4. How could that possibly be a bad thing? :grin:

    Acutally if I spilt petrol all over myself and was standing next to it, maybe it wouldn't be good.
  5. ever watch the V8's ?
  6. This is caused by a build up of unburnt fuel getting into the muffler. In other words your bike is running too rich now. The carbs may need rejetting so that they put the correct amount of fuel into the engine.
  7. don't bet on it.

    there is a phenomena with CV carbs where if the idle mixture is too lean, they draw extra fuel on a closing throttle.

    this dumps in the pipe and hence the dramatics.

    There is a good explanation on one of the Mikuni sites, but I can't find it at the moment.

    Either way get the carbs tuned to suit the pipe. You may never totally eliminate the noise, but it could get better.
  8. Theres a mod for that, either on the Hyosung forum, or the Hyosung dealer should be aware of it. off the top of my head I think they block a emission tube.
  9. Yeah, I took a look at the Korider site and they talk about stuffing ball bearings in emission hoses to block them off etc...I may just live with it for a while and get the Carbs tuned once I desrestrict the bike provided that it won't damage the engine or pipe until then...That is my main concern. Thanks for the feedback so far.
  10. Thankyou...That relieves the worries a little...

    Can I still have my Carbies tunes even though I have the restriction slides in them or is that pointless?
  11. Yes but how much longer are you going to be on restrictions?

    The Hyosung principle of restricting the slide movement is troublsom in that it throws out your main jet settings.

    Perhaps you could have your idle mixture looked at and leave it at that until you put the post restriction slides in.