Overheating at 55 degrees?
Elite HDF Member
Joined: Nov 2010
Posts: 3,846
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From: Simi Valley, CA
I am aware of EITMS (Engine Idle Temperature Management System) which I believe shuts off the fuel to the rear cylinder when the head temperature reaches the cut off point. My bike has this on it. From what I've read on here and on HD's web site, this system is primarily for rider comfort and not for the engine.
The OP mentioned a system that alternated cylinders just before shut down. I had never heard of this system or seen it mentioned on here before.
It may be real, I've just never heard of it before now.
The OP mentioned a system that alternated cylinders just before shut down. I had never heard of this system or seen it mentioned on here before.
It may be real, I've just never heard of it before now.
As far as the purpose of the EITMS goes, rider comfort vs. engine self-preservation, the owners manual says nothing about rider comfort, but does state that the system will work to cool the engine. (Although that's a pipe dream in reality. It may slow the rate at which the temperature continues to climb, but it will not cool the engine down). The HD website does imply that the system is for rider comfort. What it's really for? Your guess is as good as mine and whichever you choose it doesn't do a very good job at either.
As for idle speed, it remains constant with or without the EITMS engaged.
Last edited by 2black1s; Dec 14, 2011 at 11:42 PM.
Outstanding HDF Member
Joined: Aug 2009
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From: Puyallup Wa.
Op descripton sounds exactly how my bike acts. I was surprised to because temps were high 40° outside hearing get a tune and lose cat is getting old. my bike got NO cooler with tune(s change of pipes cams etc.
Outstanding HDF Member
Joined: Jan 2010
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From: earth
From the TTS Mastertune tuning guide May 2010:
1. MODE 1- AFR Enrichment
2. MODE 2- Skip Fire /Rear Cylinder Shutoff
MODE 1 will be activated under the following conditions:
1. Engine temperature exceeds 142C(287F)(Sportsters 230C/446F)
2. Engine RPM is less than 1200 RPM
MODE 2 ( Big Twins Only) Activates if MODE 2 is active AND:
1. Engine temp exceeds 155C (311F)
2. Vehicle speed is less than 1-2 KPH
Note that sportster temperatures are higher due to the location of the temperature sensor and use only EITMS Mode 1 (AFR enrichment)
Note that EITMS takes over AFR control when active and user AFR tables are ignored
Thats all the info I got, I dont know if mode 2 actually has 2 parts where it alternates firing front and rear and then shifts to completely shutting down the rear. Might be something in a later model owners or service manual
Its hard to diagnose a concern like this over the web, there might not be a legitimate deficiencey but then again maybe there is. I would ask that dealer tech to show me in writing the function he is talking about.
Keep in mind the OEM temp sensor is located in the front cylinder head, I typically see rear cylinder temps as much as 30 degrees higher depnding on conditions, so when EITMS kicks in at 311F the rear can be upwards 340F, it amazes me that folks are surprised at how much heat they feel when they are basically straddling the rear cylinder and exhaust.
1. MODE 1- AFR Enrichment
2. MODE 2- Skip Fire /Rear Cylinder Shutoff
MODE 1 will be activated under the following conditions:
1. Engine temperature exceeds 142C(287F)(Sportsters 230C/446F)
2. Engine RPM is less than 1200 RPM
MODE 2 ( Big Twins Only) Activates if MODE 2 is active AND:
1. Engine temp exceeds 155C (311F)
2. Vehicle speed is less than 1-2 KPH
Note that sportster temperatures are higher due to the location of the temperature sensor and use only EITMS Mode 1 (AFR enrichment)
Note that EITMS takes over AFR control when active and user AFR tables are ignored
Thats all the info I got, I dont know if mode 2 actually has 2 parts where it alternates firing front and rear and then shifts to completely shutting down the rear. Might be something in a later model owners or service manual
Its hard to diagnose a concern like this over the web, there might not be a legitimate deficiencey but then again maybe there is. I would ask that dealer tech to show me in writing the function he is talking about.
Keep in mind the OEM temp sensor is located in the front cylinder head, I typically see rear cylinder temps as much as 30 degrees higher depnding on conditions, so when EITMS kicks in at 311F the rear can be upwards 340F, it amazes me that folks are surprised at how much heat they feel when they are basically straddling the rear cylinder and exhaust.
Last edited by fabrik8r; Dec 15, 2011 at 06:36 AM. Reason: add content
Outstanding HDF Member
Joined: Jan 2010
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From: earth
I believe that is the description of the OEM EITMS functions, not peculiar to TTS.
Road Master
Joined: Jun 2011
Posts: 974
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From: Chesapeake Virginia
I have true duals and when I am at a long traffic light on a hot day (85-90+) I most definatley get some relief from the heat coming of of my rear cylinder exhaust pipe that is 4 inches below my thigh when EITMS activates. If you crack the throttle you van feel it imediatly heat up through the delay to re engage the EITMS. Stop and go can't tell as much due to constant throttle ups but I know it is better than not having it.
My shovel will not run on the rear cyl alone. As I understand it was all HD's back then. Not sure if these newer Fi bikes will or not. I haven't tried it and probably won't.
My shovel will not run on the rear cyl alone. As I understand it was all HD's back then. Not sure if these newer Fi bikes will or not. I haven't tried it and probably won't.
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Stellar HDF Member
Joined: Sep 2007
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From: Vancouver Island B.C.
No. The difference is that the TTS will skip fire the injectors to both cylinders instead of just the rear.
Elite HDF Member
Joined: Nov 2010
Posts: 3,846
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From: Simi Valley, CA
Back to the original question... I've said this many times in previous threads and I'll say it again here. The best solution to prevent engine overheating in congested traffic and prolonged idle conditions is an Engine Cooling Fan! They flat-out work! You'll never feel your EITMS kick in again with a properly functioning Engine Cooling Fan.
Here's a link with some testing I did to substantiate how well the fan works... https://www.hdforums.com/forum/tourin...test-data.html
And here's a link to a promising system that a another forum member is developing... https://www.hdforums.com/forum/tourin...tem-again.html
Last edited by 2black1s; Dec 15, 2011 at 11:35 AM.