Hunting and High idle permanent fix! - TRIAL

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I have not , and mine is working good at all temps cold , hot and never a stall . Is it possible the throttle butterflies are a bit too closed ? What is your raw throttle voltage closed ? Mine is 1.01V final setting and fully tested cold and hot .. But , I would contact SCS and get some advice if it were me. Are you running the SC Typhoon or the SCS Delta 400 ? I am running the SC Typhoon currently. There is a internal ECU pressure sensor can you make use of that ? Also , If you have not checked , make sure the passages are clear in the throttle body like (City Garage) suggested in their post .
 
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All, my bike is stalling when its a bit warmer let’s say when I have to stop for a streetlight. And I was thinking of placing a inlet pressure meter connected to the scs to correct for this stalling problem. Because it currently the ecu goes to it’s base map at low rpm. Did someone of you thought about this already? Modern bike And race bikes use this already for years.
if the bike just started to do this after x amount of miles I would check other things first. There are corrections for temperature in the ECU but again check for other issues before doing anything else.
 
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All, my bike is stalling when its a bit warmer let’s say when I have to stop for a streetlight. And I was thinking of placing a inlet pressure meter connected to the scs to correct for this stalling problem. Because it currently the ecu goes to it’s base map at low rpm. Did someone of you thought about this already? Modern bike And race bikes use this already for years.

Do you have a lock nut on the throttle stop ?
 

Sdonders

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Do you have a lock nut on the throttle stop ?
No I don’t. I set it once with Sxtune and locked it with loctite. I didn’t have any problems until recently since it’s a bit warmer again. I will check the trottlestop again and see if its changed. Thanks for the suggestion.
 
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I adjusted the reach of the idle motor into the IAM cap . I did this by decking the flange of the cap just under 1mm . About .032 inch I measured . That was all it needed . After that it was a matter using the software to set the throttle screw using SXCar when the engine was at 120 deg C . I had used two box fans to help cool it down . There is a lot to talk about , but I will just take questions and give my answers if a member asks something specific.

** PLEASE NOTE ** I am now using the SCS Delta 400 ECU . The Delta 400 does not need the Decked (- .031 in.) IAM Cap . These mods apply to the SC Typhoon only . All of my SCS Delta 400 info will be in the Delta 400 Users Group Thread.
 

Sdonders

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if the bike just started to do this after x amount of miles I would check other things first. There are corrections for temperature in the ECU but again check for other issues before doing anything else.
Yes you are right. I should first check other stuff. I didn’t really paid attention on this and will first analyze it a bit further. Thank for the wake up call.
 

Graeme Mitchell

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I know this thread has been running a long time and apologize for going back to the issue of revs hunting but I have been able to resolve it. Like some others, I get this problem only after giving the bike (Omex ECU) some stick and becomes apparent at the first stop at lights/ junction. The engine is hunting between 1500-1800 revs which probably sends out a signal I am up for a dice! The temporary fix is to switch off the engine, count to 10 then start up again. Not great if the lights change so decided to block off the O2 sensors. Worked liked a dream for a couple of days but the issue progressively returned., first holding slightly higher revs then eventually the hunting. Will reconnect sensors. Any thoughts?
 

BritTwit

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Check the IAM mounting screws.

 
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When you say block off , do you mean the O2 sensor delete resistor plugs ? Is it possible you have lost your adjustment on the throttle valve set screw ? When you start the bike in the morning is it ok until hot ? You may need to reposition the throttle valves at closed again. I know you probably don't have any way of seeing the throttle position so you will have to start from scratch. First make sure no air leaks in the IAC hoses etc.. Now back the set screw all the way off (count the turns) until the throttle valves are completely closed (set screw is not touching the throttle valve cable wheel) .. Now see if bike will start and idle. If successful , adjust set screw until just touching the throttle wheel . Now only 1/8th turn of the set screw more, use a lock nut (4mm x .7 pitch) to lock it down. This should get you close enough until you can get it to a dealer that has the OMEX software and can help you more.
 
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Graeme Mitchell

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Check the IAM mounting screws.

is "IAM" the Idle motor assembly?
 

Graeme Mitchell

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When you say block off , do you mean the O2 sensor delete resistor plugs ? Is it possible you have lost your adjustment on the throttle valve set screw ? When you start the bike in the morning is it ok until hot ? You may need to reposition the throttle valves at closed again. I know you probably don't have any way of seeing the throttle position so you will have to start from scratch. First make sure no air leaks in the IAC hoses etc.. Now back the set screw all the way off (count the turns) until the throttle valves are completely closed (set screw is not touching the throttle valve cable wheel) .. Now see if bike will start and idle. If successful , adjust set screw until just touching the throttle wheel . Now only 1/8th turn of the set screw more, use a lock nut (4mm x .7 pitch) to lock it down. This should get you close enough until you can get it to a dealer that has the OMEX software and can help you more.
Hi Tony
1. The O2 sensors capped off with the resistor plugs.
2. Idle is fine when I start and carry on at say commuting speeds. It's only when on the open road and working the engine the hunting starts. It does correct itself once the engine turned off. and left to cool for a short while.
3. will have a look at throttle set and see if any issues there
 

BritTwit

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is "IAM" the Idle motor assembly?

Yes.

The old post link has an exploded view of the assembly showing the screws that secure the idle air motor to the throttle body.
Just check that the screws are secure, not loose, but don't over tighten them or you will strip the threads.
 
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Although there are probably quite a few items that cause this problem, when mine was racing to 2400 to 2800 I had found the IAM motor flange screws, 2MM mounted into a black plastic flange had backed out first a few turns causing the under side of the flange to form a gap allowing unwanted air to get sucked in. Tightened up, symptoms stopped for a few months. Did it again....man...barely a turn, problem ceased. The stiff bent hose is putting leverage on it and causing it to separate. That flange is a pretty soft plastic and I'm not sure how long its going to hold up with me constantly tightening on it. Tempted to black duct tape the gap if it comes back again but that pretty ugly.
 

Graeme Mitchell

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Although there are probably quite a few items that cause this problem, when mine was racing to 2400 to 2800 I had found the IAM motor flange screws, 2MM mounted into a black plastic flange had backed out first a few turns causing the under side of the flange to form a gap allowing unwanted air to get sucked in. Tightened up, symptoms stopped for a few months. Did it again....man...barely a turn, problem ceased. The stiff bent hose is putting leverage on it and causing it to separate. That flange is a pretty soft plastic and I'm not sure how long its going to hold up with me constantly tightening on it. Tempted to black duct tape the gap if it comes back again but that pretty ugly.
Thanks, had a check and the idle motor assembly appears secure. Have tinkered with idle throttle setting as suggested by Tony and refitted the O2 sensors. Will take the bike out for ride tomorrow and see if any improvement.
 

Graeme Mitchell

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With the adjustments made the tick over is at 1200. After warming the bike up the hunting returns but is less pronounced goes between 1400 to 1700 ish. Again turn off the bike wait a little bit and returns to 1200.
I can live with this but will be pleased when there is a definite fix.
Thanks to all for your help and interest
 
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What year is your bike ? I think you said OMEX ecu . If you email the service department at Norton I am sure they can help. Are you willing to try a new Idle Motor ? And to clamp all the Idle Motor hoses to ensure they are tight . I wish I was your neighbor to help you. Find somebody with the Omex software , they may recommend a re-load of the factory bin file . I hope they don't tell you to replace the ECU or the throttle body ! There are other things to try , read all the threads and see what you are willing to do.
 
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Graeme Mitchell

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What year is your bike ? I think you said OMEX ecu . If you email the service department at Norton I am sure they can help. Are you willing to try a new Idle Motor ? And to clamp all the Idle Motor hoses to ensure they are tight . I wish I was your neighbor to help you. Find somebody with the Omex software , they may recommend a re-load of the factory bin file . I hope they don't tell you to replace the ECU or the throttle body ! There are other things to try , read all the threads and see what you are willing to do.
Hi Tony
The guys at Donnington have already looked at this a few times at service intervals. Every time they say it runs fine only to find after a good trip out it returns. I think I will live with it as it is now no so bad.
 
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Read in the Norton Facebook page, a fella had racing idle on his Dommie 961. Found a crack in the hose leading to the IAM flange. Another spot for unwanted atmospheric air.
 

Graeme Mitchell

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Read in the Norton Facebook page, a fella had racing idle on his Dommie 961. Found a crack in the hose leading to the IAM flange. Another spot for unwanted atmospheric air.
Ok, so I removed the hose between the airbox and the IAM (it a reinforced rubber s-shape) although I couldn't see any cracks it is crammed between the two connectors and did have a plastic binding wrapped round. Not sure if this is part of the hose or something done at a service. Anyway, since I had the hose off I added some sheat shrink. Well now, there is a difference of sorts. I am getting a bit of hunting just before stopping but settles down quickly to 1200 revs which is a big improvement. Not sure why but could be leaking at the connectors and simply refitting them has done the trick.
 
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