Really high idle

[tod.branko_imp]

Probably not relevant here but I'll mention it.
My long gone Harley Softail was programmed to kick into high idle if the oil temperature got above a preset limit. The idea is that with the engine on the brink of overheating they want oil circulating faster to cool the engine. Given that I'm sure that they've tested this thoroughly and it works as an emergency measure, it kind of surprised me to read about this in the manual because I would have just assumed that higher rpms automatically meant higher temps, but then this is the idle speed and the engine isn't running under a real load when this happens so I guess it makes sense. It had happened to me a few times on that bike and once traffic got moving and the engine cooled down the idle speed would go back to normal.

It makes sense on a Softail to a certain extent if we are talking about a twin-cam because there is a design flaw with the oil pump for the rear cylinder. From what I remember it wouldn't create enough pressure on idle so in stop and go traffic the cylinder would dry up and seize. HD have since implemented the system where the rear cylinder shuts down completely on idle and it's a system they are utilizing on the M8 even though it's water-cooled.
There is no system of that kind on the CB1100 (not officially anyways)
I heard a YouTuber once talk about a system on the CB1100 that allegedly skips a spark on random cylinders when the temperature goes too high, and I tried to find any official information on this, I even hit up a guy I know here who is a regional manager for Honda motorcycles here in the ME, and he told me that that's not the case, only cooling technology Honda is utilizing is the machining tech that allows them to cut the cooling fins thinner and longer (deeper) and that supposedly dissipates heat better.

'14 CB1100 STD 5 speed

[furious_blue_imp]

Probably not relevant here but I'll mention it.
My long gone Harley Softail was programmed to kick into high idle if the oil temperature got above a preset limit. The idea is that with the engine on the brink of overheating they want oil circulating faster to cool the engine. Given that I'm sure that they've tested this thoroughly and it works as an emergency measure, it kind of surprised me to read about this in the manual because I would have just assumed that higher rpms automatically meant higher temps, but then this is the idle speed and the engine isn't running under a real load when this happens so I guess it makes sense. It had happened to me a few times on that bike and once traffic got moving and the engine cooled down the idle speed would go back to normal.

It makes sense on a Softail to a certain extent if we are talking about a twin-cam because there is a design flaw with the oil pump for the rear cylinder. From what I remember it wouldn't create enough pressure on idle so in stop and go traffic the cylinder would dry up and seize. HD have since implemented the system where the rear cylinder shuts down completely on idle and it's a system they are utilizing on the M8 even though it's water-cooled.
There is no system of that kind on the CB1100 (not officially anyways)
I heard a YouTuber once talk about a system on the CB1100 that allegedly skips a spark on random cylinders when the temperature goes too high, and I tried to find any official information on this, I even hit up a guy I know here who is a regional manager for Honda motorcycles here in the ME, and he told me that that's not the case, only cooling technology Honda is utilizing is the machining tech that allows them to cut the cooling fins thinner and longer (deeper) and that supposedly dissipates heat better.

'14 CB1100 STD 5 speed

It makes sense on a Softail to a certain extent if we are talking about a twin-cam because there is a design flaw with the oil pump for the rear cylinder. From what I remember it wouldn't create enough pressure on idle so in stop and go traffic the cylinder would dry up and seize. HD have since implemented the system where the rear cylinder shuts down completely on idle and it's a system they are utilizing on the M8 even though it's water-cooled.
There is no system of that kind on the CB1100 (not officially anyways)
I heard a YouTuber once talk about a system on the CB1100 that allegedly skips a spark on random cylinders when the temperature goes too high, and I tried to find any official information on this, I even hit up a guy I know here who is a regional manager for Honda motorcycles here in the ME, and he told me that that's not the case, only cooling technology Honda is utilizing is the machining tech that allows them to cut the cooling fins thinner and longer (deeper) and that supposedly dissipates heat better.

'14 CB1100 STD 5 speed
Very interesting, I hadn't heard that about the Softail. One other major change that happened on that engine was tighter bearing clearances necessitating specs for a new oil filter for finer filtration AND a boost of the idle speed to bring up the oil pressure, which I understood was intended to provide sufficient pressure to keep the tighter bearings happy. I have seen numerous youtube videos of people doing 'cool mods' to their later model Softails which include turning down the idle speed to barely sustainable, which of course will not be good for the engine because the bearings will suffer... I wonder if the problems tended to occur with bikes that had been modified like this and Harley realized that they could change 'the culture' so they had to upgrade the pump, which they actually should have done in the first place instead of just raising the idle speed and counting on that to keep the pressure at minimum. Maybe, maybe not. It sounds more likely that the reasons you give for the new pump are true. Glad I never had THAT problem with mine !
For the 1100 cooling, don't the spark plug oil cooling circuits also help with additional engine cooling > (extremely targeted cooling for sure !).

[SportsterDoc]

Max, good thoughts in your post number six.
Interesting and quite plausible theory about the permanent magnets being affected by heat. If we knew the magnetic material we could look up the Curie point.

It would be most interesting to know if Honda changed the magnetic material after 2014 model... and used different in 2013.

[dave]

It would be most interesting to know if Honda changed the magnetic material after 2014 model... and used different in 2013.
[/quote]

Hi Doc. Doesn't the Curie point temperature occur at a really high (1,000 deg F +) for common metallic materials? Are the magnets in our IACVs metallic?

[Lord Popgun]

This entry on Wiki has a chart of Curie points for different materials: https://en.wikipedia.org/wiki/Curie_temperature

[max]

Doc thanks for the response and good to hear from you, it occurred to me that some failures happened after riding in high temperatures, magnets loose some of their magnetic properties at higher temperatures, weller soldering irons used magnets with different magnetic properties to regulate the tip temperature, you could hear the clicks as the micro switches reacted to the tips losing their magnetism and switched the heater off and back on when the magnetism was restored.
So i thought that it was a possibility that the permanent magnets in the iacv rotor could be affected by this phenomenon.

On the other hand it is well known that updating the software has also alleviated this problem.
So i think it is a combination of software which supplied just enough energy to the iacv to make it work but as soon as magnetic force was reduced it permanently crippled the operation whilst the "good" software provided enough energy ( enough pulse with ), this is my best guess, cheers guys

[SportsterDoc]

Dave, it varies greatly, as per the link posted by Popgun.
Doubt we will ever know the material(s), but Max's temperature theory has merit.
Max, if only we knew the actual software update details!

4800 miles on the Street Twin since May 25 and no re-occurrence of August 2018 eye issues.

I was in two Honda dealers this week (Carter Power Sports and Rancho Power Sports), asking about any CB1100s. Was told that Honda's warehouse(s) are empty....true JIT manufacturing now.

Oh well, I am reasonably content with my 900cc parallel twin in cobalt blue.

https://ultimatemotorcycling.com/2021/02...ast-facts/

As much as I resisted water cooling, it is averaging 61 MPG!

Longest one day trip was over 500 miles, from Las Vegas to Bryce Canyon National Park, Zion National Park.

[pdedse]

Dave, it varies greatly, as per the link posted by Popgun.
Doubt we will ever know the material(s), but Max's temperature theory has merit.
Max, if only we knew the actual software update details!

4800 miles on the Street Twin since May 25 and no re-occurrence of August 2018 eye issues.

I was in two Honda dealers this week (Carter Power Sports and Rancho Power Sports), asking about any CB1100s. Was told that Honda's warehouse(s) are empty....true JIT manufacturing now.

Oh well, I am reasonably content with my 900cc parallel twin in cobalt blue.

https://ultimatemotorcycling.com/2021/02...ast-facts/

As much as I resisted water cooling, it is averaging 61 MPG!

Longest one day trip was over 500 miles, from Las Vegas to Bryce Canyon National Park, Zion National Park.

Which is just stunningly beautiful!!! Very happy for you SportsterDoc that you were able to come back to riding.

.............................................................................>

[SportsterDoc]

Thank you, pdedse.
Good group on this forum. You all are missed!
Only a few upgrades on the Street Twin:
1. Dart Marlin fly screen
2. Givi tail rack
3. Factory center stand
4. Removed the snorkel interior, as debris was not accumulating evenly on the air filter
5. Replaced H4 with an LED: Auxito USM4H4-041: PLUG AND PLAY ON ANY H4, CLOSE TO SAME COVERAGE AS H4 BUT MUCH MUCH BRIGHTER. $19.99 from Amazon.

[Cormanus]

Don’t be a stranger, Doc.