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Tuning 2013 Hyo after free flowing pipe fitted?

Discussion in 'Maintenance and Servicing' started by monkeyboy666, Oct 25, 2013.

  1. I fitted an aftermarket pipe to replace the bloody awful factory exhaust and the bike has been running slightly rough ever since which I assumed was just a back pressure change from the factory pipe. But I had it serviced today and Luke from 60 Degrees said a cylinder may be misfiring...he said this because he felt the coughing and farting that usually accompanies a more free flowing pipe...the back pressure thing...seemed a bit more pronounced that he'd expect from just an exhaust change and could possibly be a misfiring cylinder.

    Anyway, the bike is under warranty so I went into Peter Stevens' service department (who I don't have a whole lot of confidence in tbh) and the dude there told me that my bike's ECU will relearn new air fuel ratios...but only within certain parameters. The AFR's created by the new pipe might be outside these parameters. It's a Hyosung after all, so I'd assume the relearn ability of the ECU...or is it the PCM...would be limited at best.

    So the PS dude said they would hook it up to some diagnostic tool I can't remember the name of, check the ADR's, redo the throttle position sensor (or words to that effect)...so the computer can play nicely with the changes made by the new pipe and run the way it did when it rolled out of the factory.

    Alright...so my question is: Is the service department guy full of crap and creating about 150 bucks in labour costs for nothing or is this necessary to get the bike running the way it should? Is the bike's computer able to be adjusted to the point where altered AFR's will be rectified or does the ECU on these bikes only allow for minimal, if any AFR adjustment?

    TBH I don't think a cylinder is misfiring because the fartiness/spluttering/loss of power at certain revs only started when I fitted the new exhaust, but I'd like to know for sure. And I'd like to get the bike running at it's optimal level...and don't mind paying to have this done. I just don't want to get fed a line of BS by some service department gimp and fork out money for no real benefit due to my lack of expertise and understanding in this area.

    If anyone does have an answer and is able to explain in dumbass terms so I can follow it...that'd be really helpful. If the answer is, "Let the service dept. guys do what they need to do', then that's fine with me.

    Hopefully that made some sense.

    Thanks guys [​IMG]
    • Like Like x 1
  2. I had a hyosung gv650 that had full system on it, I brought it second hand. Mine used to run rough alot down low. Kind of like it was missing. It was covered under warranty. After the dealer did alot of stuffing around throwing parts at it I suggested a computer reset. That's what worked in the end. It then ran perfect. They didn't charge me anything.
  3. #3 monkeyboy666, Oct 25, 2013
    Last edited: Oct 25, 2013
    I'll get them to plug in the diagnostic thingo to make sure it's not a misfire though just to rule that out. But before then I'll reset the ECU, give it at least 24 hours to relearn the AFR's and see if that makes it run a bit smoother.
  4. Having the fuel offsets reset will help it learn the new airflow quicker, and your openloop area will more than likely be leaner aswell. I would let oldmate check it out if you want the most from your engine you can get.
  5. That if it works the way I'm familar with. :)
  6. Resetting the ECU will help it relearn.

    The bike will always pop on deceleration. To stop it, you'll need to block the AIS.
    You wouldn't have heard the popping with the original exhaust as the unburnt fuel is burnt off in the catalytic converter.
    If you have the original exhaust, pop it back on and see if it still runs rough. It could be just a coincidence, but, you may need to adjust your TPS.

    Check out www.korider.com/
  7. #6 monkeyboy666, Oct 26, 2013
    Last edited: Oct 26, 2013

    To confirm, I just do that battery disconnect thing yeah? Reconnect after a while and let the ECU do its thing right?

    Cheers for the replies incidentally, much appreciated :)
  8. Oldmate, ps dude, what ever you want to call him.
    Disconnecting the battery to reset your ecu? what witch craft is this?
  9. That's a no then? Diagnostic tool required? Get off the pipe and clarify man! o_O
  10. Parameters like this I don't think are held in volatile memory so disconnecting the battery will not erase them. The ECU has to be told specifically to erase them. AFAIK
  11. Disconnecting the battery did nothing for me
  12. Hyo's have an ecu?

    Wighout seeing/hearing.... I suspect it's unburned fuel popping in the pipe.

    Low end power loss is probably cause hyo's aren't race bikes... They're tuned for their low end and it probably needs a bit of back pressure for best results, open pipes are about peak flow so hopefully it helps up top.
  13. Unburnt fuel pops in the pipe when it's cold...after it warms up it stops.
  14. Cuz fuel won't burn when it's hot?

    I think what you mean is when the bikes cold it puts even more fuel in - cold start enrichment.

    That's different to normal rich running unburned fuel in the pipe
  15. That makes sense. It pops when it's cold, but not after it warms up...so the cold start enrichment you mention (which I had no idea existed until I read your reply) would explain that. :)
  16. It's kinda the same issue... Just when it's cold it enriches more so it will pop more..... Will probably do it when hot too as it pulls timing and pours in fuel. All to do with preventing pinging/knocking
  17. You can tune that decel pop out by either drowning it or starving it, also a custom tune will fix any lean or rich areas, giving you a better running engine, but having a custom tune done won't be cheap. At the moment your engine is tuned to your oem exhaust, changing the exhaust can make a big difference.
  18. .... which begs the question.... if it's not doing damge, is it really worth the expense of custom tuning a hyo, or can you live with the popping till you get something else?
  19. The popping isn't a problem...I like it in fact. The low end power loss felt like a misfiring cylinder to Luke from 60 Degrees. That's what I really wanted to get sorted (if it is misfiring) the rough running at low revs is something I can live with. I'll just get them to hook up a diagnostic tool and make sure there's nothing wrong and leave it at that I reckon.

    There's no point in tuning it though...as long as no damage is being done.
  20. gotta say... a cylinder missing on a twin is pretty significant... its not slight power loss it's friggin wonky.... ive had our VTR run on 1 cylinder and it wasn't happy... it's very obvious even if its intermittent so i highly doubt it's gonna be a problem...

    the popping indicates your probably getting enough fuel for the increased air flow... i'd say it's just lacking some bottom end oomph cause of the drop in back pressure...

    but hey, get it checked out and let us know :)
    • Agree Agree x 1
  21. ^ I'm leaning towards it being a back pressure drop too. But hey, getting it checked out and letting them have a fiddle with it is alright with me, as long as it improves it rather than just cost me money for nothing.