Hunting and High idle permanent fix! - TRIAL

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It can be done to any 961. Do you need to ? I thought only the SC 961 suffered from the high idle issue ? The problem with the OMEX is no software to monitor your throttle screw setting . But it can still be done. Get yourself a new IAM cap from Norton before you start . This way if you mess up you got something to fall back on.
 

ntst8

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Perfect, thank you.
Oops the comment initially referred to Tony's pictures and description a few posts back.
The suggestion of accurately machined caps sounds good, as long as postage downunder is vaguely affordable.
 
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If its going to mess up that is usually when it acts up (when hot) . It is worth a try and I think it will work too . Install the resistor O2 eliminator plugs too , the bike will run better in the 2000 to 3000 rpm range .
 
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I was experiencing hi idle when hot. I ordered but yet to install the O2 sensor eliminator caps.
I was idling at 2400 when hot. The O2 sensors helped but not cured. Also, that IAM flange still manages to get a gap on the bottom due to poor leverage from that stiff bent hose that's attatched to it. There is only so much tightening of those 2mm bolts that a plastic flange will deal with before wearing out. Also, forgot to apply heat paste to head temp sensor when switching to Bosch if that means anything.
Now when hot I get one of 2 symptoms, and I mean hot in the summer months. It ran great all Fall and Winter, most of the Spring. Occasionally, on a hot day, I'll get 1800 rpm idle. Usually I get a slower idle and it will either stall or catch itself right before stalling, surge, then normal out. So, two things on the list, heat paste and the throttle body gasket that I still have but neglect to make the time for.
Its boating season.
 
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Thought we'd jump in here since we have been fighting these issues.

We spent the better part of a month looking at these issues along with consulting Richard-7 on a 2015 with an SCS ECU in the shop. One of the big issue we found was power going to the Idle Air Control Valve on start up from the ECU. If there was any hiccup with the relays or other problems when the start button was pressed then it would immediately start a hunting idle condition because the IACV was not getting the voltage it needed to retract/extend as needed. When the start was flawless the idle rose as required by the IACV then settled to a nice 1200-1250 idle.

We went through the process of having the SCS ECU unlocked in order to have access to all the data the ECU provides which really helps troubleshooting.

The IACV Norton used basically comes from a Renault Clio and is not so easy to find in the USA.

Air leak issues are quickly diagnosed and while decking sounds good we found that the housing and the Idle Air Control Valve(IACV) mate just fine.

Other issues we found were that the IACV intake crossover tube was gunked up with oil by not letting enough air into the intake. This was from the oil mist and crap pushed into the air box where the IACV gets its air from. Pull the spark plugs and clean out the crossover then rotate the engine while the plugs are out to purge the cleaner you sprayed in there

The hose from the IACV was not clamped properly on the intake and IACV end. (This one of the things we noticed the best improvement)

With all the above, we were able to get a consistent idle.

Hope that info helps
 
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NO LONGER A TRIAL , NAS VALVE REMOVED PERMANENTLY !



This is in the Bank earning interest folks !
 

iwilson

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Good work Tony, I think the idle problem is probably multi-faceted and many owners have solved different pieces of what some might think is a relatively simple problem. Some have fixed symptoms (removing o2 sensors), others have delved deeper. - Tony, myself and Richard. My slightly crude method of removing the entire idle air control system and plugging the shared idle air pipe (which is a major part of the problem and the cause of many fouled plugs) is one solution that I rigorously scientifically tested.

Would love to see a few more videos showing solutions with a cold and hot start. There is more I could do, but to be honest the bike starts hot or cold (middle of winter here), without any idle control which shows actually how good this engine is! The second video is a middle of the winter start from cold!


 
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Good work Tony, I think the idle problem is probably multi-faceted and many owners have solved different pieces of what some might think is a relatively simple problem. Some have fixed symptoms (removing o2 sensors), others have delved deeper. - Tony, myself and Richard. My slightly crude method of removing the entire idle air control system and plugging the shared idle air pipe (which is a major part of the problem and the cause of many fouled plugs) is one solution that I rigorously scientifically tested.

Would love to see a few more videos showing solutions with a cold and hot start. There is more I could do, but to be honest the bike starts hot or cold (middle of winter here), without any idle control which shows actually how good this engine is! The second video is a middle of the winter start from cold!


Hello again Iwilson , Engineers can solve problems if they are allowed to . At Norton they must have been shackled ! And thank you .
 

speirmoor

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That's the ball cock valve you see above . (North American Solution)
Love it! Now 'splain this to me. Was there something else there before or you're eliminating the IAV's function altogether?
I wish I was your neighbor , I would help you get this done in a quick afternoon !
Many thanks but my main issue is the heat. I have no room to work inside on my bike and we're on the 5th week of 80 deg+ weather. My concentration levels really drop in this heat so I'd be afraid of dropping the tank on the ground or doing something else stupid. It can wait.
 
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Love it! Now 'splain this to me. Was there something else there before or you're eliminating the IAV's function altogether?

Many thanks but my main issue is the heat. I have no room to work inside on my bike and we're on the 5th week of 80 deg+ weather. My concentration levels really drop in this heat so I'd be afraid of dropping the tank on the ground or doing something else stupid. It can wait.
The ball cock valve in the picture has been removed now. This was the NAS valve I spoke about last year. This is how I used to help control my idle when hot. But after using SCS software to look at the ecu idle operation , I decided to move forward with my latest fix. Which is the IAM Cap decking . I suspected IAM reach to be the root issue of the hot high idle . I apologize but I just assume that everybody reads all the posts but its just not so as I clearly see now.
 

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