1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Hunting and High idle permanent fix! - TRIAL

Discussion in 'Norton Motorcycles (Modern)' started by richard-7, Sep 14, 2018.

  1. richard-7

    richard-7

    Joined:
    Feb 24, 2014
    We've been reluctant to share this and again - TRIAL USE ONLY!!!

    Since February 2018 my dad was sick of the hunting idle. He was determined to solve it. And he did. But here's the back story:

    Seems like the newer ECU's have more power to better control the IDLE AIR MOTOR but not everyone wants to spend money on a new ECU. And on top of that, there are still a few bikes with the new ECU's that have that annoying hunting idle and high idle situation. And there are some IDLE AIR MOTORS that are faulty. And there are VALVE BODIES that are adjusted incorrect or poorly made with the butterfly flaps not tuned. ????? Meaning one flap when closed has a .003" larger gap then it's neighbor. All around sucks! and makes for an unhappy owner. If a custom "hand made" builder were to assemble this bike, every detail would be looked over and tuned. So that's what we are doing.

    So even after you tune the flaps, clean the IAM, change all the sensors, re-map the bike. With the pre-2016 bikes there still seems to be this issue. So my dad warmed up his bike to full running temp. put a ball bearing in the hose between the IAM and the air box. Then, cranked up the idle screw so it actually does control the idle. BAM!!!! Perfection. Like a new bike.

    I did this to mine about 3 weeks ago. BAM!!! a new bike. Why did I wait so long to try this??? The idle will always drop smoothly to where you told it to and NEVER EVER CLIMBS or hunts!!!! Say you're doing 120km/h at 4,800 rpm and pull in the clutch. ....BAM!!! PERFECTION!!!!

    This comes with a small sacrifice though. Cold starting is non existent. You have to hold the throttle when starting for about one minute.

    Is it worth it?? Definitely!!!

    Do I miss perfect cold starts? Definitely!!!

    Would I ever take out the ball bearing and go back to the way it was??? NEVER!!!!


    GOOD LUCK OWNERS!!! Try if you dare. And again. Trial only.

    *******Only do this if your bike is out of warranty and you feel 100% comfortable doing so.*****
     
    Britfan60, Fultonrn, MxMartin and 2 others like this.
  2. Britfan60

    Britfan60 VIP MEMBER

    Joined:
    Jan 5, 2014
    I don't have a problem with cold starts. The hunting is minimal but there. Starts, hunts up and down15 to 30 seconds, settles to 1200. However, after a thrashing, idles at 1500. I hate that. If it's in the 90's out, sometimes idles at 1800 to 2K. REALLY HATE THAT. However, if I shut it down, say at a red light and restart, it'll settle down. Thanks once again for your dad and you for doing all of the experimentation. No one likes to be the guinea pig.
     
    contours and Fultonrn like this.
  3. kommando

    kommando

    Joined:
    May 7, 2005
    If you added a second hose and an engine temperature contolled valve you could have a clear route hose for cold starts and ball bearing hose for normal running.
     
    contours likes this.
  4. richard-7

    richard-7

    Joined:
    Feb 24, 2014
    Good thinking. Thanks.
     
  5. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Interesting, Richard. I have a similar, but a bit different experience on my 2015 Sport. I have replaced the SC ECU with an updated SC-Delta 400, which is not locked, so I can play with the programming. It allows me to disable the IAC in the ECU, and the result is the same. Really nice, stable idle when warm, but terrible cold starts. It takes me at least 3 starts, sometimes 4 before it will keep running when cold. I'm hoping to play with the IAC programming parameters, as well as the cold start mapping, but haven't got to it yet. With the original SC ECU I had the same problems others have reported, poor cold starting and erratic idle, both cold and warm.

    Ken
     
    contours likes this.
  6. BritTwit

    BritTwit

    Joined:
    Aug 25, 2009
    My issue as well.
    Hoping to send my SC ECU to Delta this winter to unlock.

    I have never had erratic or high idle.
    My issues are cold start, cold idle, slow response when blipping throttle for down shifts.

    Once warm, my 961 is a sweet ride.
     
  7. comet

    comet VIP MEMBER

    Joined:
    Aug 23, 2016
    Richard, I reckon I will try this. It's the one thing that takes the pleasure out of riding this bike, not knowing whether it will actually slow down when I close the throttle.

    Mine is a 2013 with the SC ECU. I noticed the high tickover issue just after the factory replaced the cylinders due to the bores dropping. It may have been there before but the bike was running poorly anyway due to the head gasket leak (the symptom of the dropped liners) and I had to wait some months for the work to be done. It's been back 3 times since for the tickover issue and each time I was told that it was fixed and the fix was a re-map, although I was never given the details of which map had been installed, despite asking. It wasn't fixed on any of the visits, the last one being September last year. I since got hold of the SC connector lead for the ECU and I can see that it has map 77-0016.

    I don't have the engineering skills of others on this forum, but neither do I have the money to keep paying for a "fix" that doesn't work and I'm looking for options that I can try myself, so thanks for sharing this.

    On a separate but linked point, my Norton manual refers to a MAP sensor. It shows it in the diagram with the ECU, and there's a note in the manual saying that the MAP sensor is incorporated into the ECU on later models. I assume the manual is referring to the original Omex ECU as I can't see a separate MAP sensor on mine. However, my question is, how would a MAP sensor operate unless it has a pipe connecting it to the throttle bodies? I thought it monitored the change in the inlet air pressure and I'm assuming it would have an important part to play in tickover and deceleration etc, so I'm interested in understanding how it works on the Norton.

    Can anyone educate me on this?

    PS - despite the tickover issue (which happens when warm and keeps the revs over 2000) I don't have any starting problems. It generally starts first time cold or hot, and that's with the 2013 battery (tempting fate there).
     
  8. Britfan60

    Britfan60 VIP MEMBER

    Joined:
    Jan 5, 2014
    Comet. Your bike and my bike (13) are evil twins. I have map 91. Bike runs well with it. I had the same symptom with 77
     
  9. BLIGHTYBRIT/SF

    BLIGHTYBRIT/SF VIP MEMBER

    Joined:
    Feb 28, 2016
    Should linking out the lambda sensors help on this prob , using those nice 330 ohm resistors in the neat plugs ( ment for the aprillia) ?
     
  10. comet

    comet VIP MEMBER

    Joined:
    Aug 23, 2016
    I was wondering about that. I've been reviewing all the previous posts and I saw your one about the 91 map. It will be on the list of possible things to try.

    Another one for the list.


    Before I start changing anything I'm trying to get a better idea of how it all hangs together as I don't want to just change things without understanding what I'm really doing. So it's a steep learning curve for me. I have determined that there isn't a MAP sensor on mine, despite the reference in the manual and on the wiring diagram. It looks like Norton were going to fit one and changed their mind. The MAP sensor take-off point on the throttle bodies has a plastic cap over it and I understand the connection to the ECU was used for the tilt switch instead. I believe there is a MAP sensor on the Euro 4 bikes (different ECU). I wonder if a MAP sensor instead of a tilt switch would have made the tickover, starting etc issues more manageable?

    I can see from the ECU software that there is a barometric pressure reading so I assume that particular functionality is built into the ECU.

    Another possible contributory factor that has been suggested is that the plastic Idle Air Control valve distorts when it is hot and lets in more air. Could explain why the issue occurs when the engine is warmed up.

    I saw another post where the problem was fixed by replacing the SC ECU with Omex. I'm making more assumptions here along the lines of the change really being down to the mapping rather than the ECU itself, and I can't see why the SC ECU mapping couldn't be corrected, as it's not as if the Norton is a complex engine compared to some.

    I'm currently considering getting my ECU unlocked so that someone with more knowledge would be able to tune it for my bike. I know it would allow me to disable the IAC valve, which would have the same effect as Richard's ball bearing.

    I have had a cursory look at the SC software and have found it useful. I haven't yet used it with the engine running but it allowed me to test the TPS. You can get an idea if the TPS is working from a multi-meter, but the on-screen software display gives a much finer view as you slowly move the throttle - it would be easier to see any dead-spots for example.

    Next step is to use the SC software to properly set the idle, and then work from there.

    This is all new to me, so I'm happy for anyone to jump in and point out errors in my thinking, incorrect assumptions etc., or provide any additional info.
     
  11. BLIGHTYBRIT/SF

    BLIGHTYBRIT/SF VIP MEMBER

    Joined:
    Feb 28, 2016
    Those resistor plugs have got to be the best value for money thing u can buy , £20 odd sov,s get them in couple days, whip the tank off & plug em in & away u go b4 u can say “ snap crackle & pop”
     
  12. richard-7

    richard-7

    Joined:
    Feb 24, 2014

    I tuned mine with the software. For the
    Most part is was problem free. Hence why I wasnt in a rush to try blocking it. But now blocked. Its perfect. PS i also have the resistors and map 077, catless, shorties, all bosch everything, one07 wires, iridium plugs, ethanol free 91 fuel only. This blocking and adjusting the screw was the last piece of the “perfect running” puzzle for my bike and my dads bike. We haven’t done it to anyone elses.
     
    Raphi and contours like this.
  13. Bluedog 55

    Bluedog 55

    Joined:
    Aug 3, 2015
    Interesting. You say you only run on ethanol free 91 I was with a group of bikes over the last few days and several of us with newer bikes wouldn't fuel with 91, they like me had been told only use 98 I have once used 95 due to no choice but otherwise always 98
    Do you think a lower rating fuel will make the bike run better? Mines good above 3000 rpm but a pig to ride through the city or anywhere you need to go slow for any length of time, I've done all the upgrades except iridium plugs, if I can get them what sort should I buy? Interested on any comments re fuel rating
     
  14. contours

    contours VIP MEMBER

    Joined:
    Jan 1, 2012
    Poor throttle response cannot be limited to just me and you. All I know is switching between the bikes in my collection makes for a frustrating first day.
     
    MxMartin likes this.
  15. MxMartin

    MxMartin

    Joined:
    Nov 13, 2017
    I got a new pair of bike boots the other day, if you think switching bikes is frustrating try switching to new boots, lost count of how many gear changes I fuddled! :)
     
    contours and Fast Eddie like this.
  16. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Are you inadvertently mixing up values here? Octane rating numbers in the US are different to Europe, maybe same for you guys too?
     
  17. Bluedog 55

    Bluedog 55

    Joined:
    Aug 3, 2015
    Not 100% sure we get 91, 95 and 98 which is supposed to represent octane, mostly the 91 can be E10 what they call it over here which is supposed to be 10% ethanol , I know it ended badly when I fuelled up at a discount fuel station in my 750 which had a fibreglass tank and with ethanol fuel, it doesn't have one anymore
     
  18. ntst8

    ntst8 VIP MEMBER

    Joined:
    Feb 14, 2004
    Aus & NZ use the same as the UK.
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    From t’internet...

    “In the United States gas stations describe the types of gasoline based on the Pump Octane Number (PON). That number is the average between RON and MON. This causes many problems.

    If a fuel is 98 RON then it will be 93 PON -> 93 PUMP
    If a fuel is 95 RON and 87 MON then it will be 91 PON -> 91 PUMP

    Is American fuel quality bad after all?

    No, not at all. Contrary to popular belief, fuel quality in the States is as good as anywhere else in Europe. Most Americans think that because they are running 91 octane fuel, their engine will blow up. It is the same as if they were using European 95oct fuel”.

    So there we have it...
     
    Britfan60 likes this.
  20. Britfan60

    Britfan60 VIP MEMBER

    Joined:
    Jan 5, 2014
    You are correct, Nigel, however, I know of no Americans that think their engine is going to blow up using 91 Octane. Also, contrary to popular belief, America get most of its oil and is refined in America. In addition, people buying octane boosters, not realizing many of them are made from ethanol.:confused: