Rear cylinder switches off when hot.

[Roaming Wolf]

In my case it is a blend of picture one and picture 2. The sensor is the same as in the upper picture but with a different connector and I have a knock sensor as in the bottom picture. From what I see, a normal Harley 99-2017 sensor can be used. It is also 2 wires. I will need to order a female connector and reconnect the 2 wires. Already did the same job with my O2 sensors. Both are working fine.

 

[SKOGDOG]

Please let us know how it works out. Inquiring minds, etc……..

 

[Roaming Wolf]

Update. S&S confirmed that I can use a normal Harley CHT sensor, just need to wire a new connector. I checked the ignition coil and it seems to be fine. I have single fire 0.5Ohm. Measured the resistance. On the connectors it shows 0.5 and 0.5 which is normal and on the spark plug wires connectors - 11. The coils seems fine, but I ordered a new one just in case. However, it might be another, much more simple issue. The coil is mounted with 2 bolts to a metal plate that, I believe, grounds it. If removed, the bike will not start, no spark. The way it is designed (and painted black) makes it super hot in our climate. There is almost no ventilation. I cleaned all the surface, put it back together, started the bike and let it idle for some time giving it some extra RPM. No issue, the rear cylinder is on and does not cut off. Will be testing more. Any aftermarket coil covers with vents?

 

[Jwooky]

I don’t think that is your issue. The case dose not ground the coil. Most to all coils are mounted to the engine, so assuming it is healthy, should it be a concern.

 

[Roaming Wolf]

I don’t think that is your issue. The case dose not ground the coil. Most to all coils are mounted to the engine, so assuming it is healthy, should it be a concern.

That is what I thought. However, I removed the cover and connected the coil separately. The bike wouldn't start. The moment I mounted it back to the metal plate, all was good.

 

[Jwooky]

Take a very close look at the terminals in the coil connector. They can get splayed out causing a weak connection. The terminals are available is needed.

Also verify the 3 pins in the coil are straight, not misaligned.

 

[Roaming Wolf]

Checked the connectors. All fine. Went for a ride. During the day time it gets very hot now. While the bike was moving everything was OK. Then I stopped at the traffic light and, suddenly, the rear cylinder switched off. After about 1 minute it switched on again and the bike was running fine, then switched off again. Parked the bike and waited till 6pm, that is when the sun starts setting down. There are 2 long traffic lights in Downtown on the way to Dubai Mall. No issue, all the cylinders were working fine. I have already ordered an ignition coil. It will be the first thing to change. Then the CHT and, hopefully, it will not get down to the ECU.

 

[Jwooky]

This is where having the ability read the data log with Protune would be invaluable.

It’s quite possible it is simply exceeding the rear cylinder limit and intentionally shutting off.

 

[SKOGDOG]

Blacktopper reminded me of a discussion we had about my 2010 Bulldog Bagger. We thought the computer would turn off the rear cylinder in the event if the engine overheating—apparently the rear gets hotter (that makes sense), So I asked Chat and it came back with this answer:
So the most accurate answer is:

• The bike’s electronics appear capable of independently cutting the rear cylinder.
• Owners and mechanics have reported rear-cylinder cutout when the engine gets hot.
• But I could not verify from an OEM manual that the 2010 Big Dog Bagger officially includes an intentional overheating protection mode that shuts down the rear cylinder.

 

[Roaming Wolf]

Blacktopper reminded me of a discussion we had about my 2010 Bulldog Bagger. We thought the computer would turn off the rear cylinder in the event if the engine overheating—apparently the rear gets hotter (that makes sense), So I asked Chat and it came back with this answer:
So the most accurate answer is:

• The bike’s electronics appear capable of independently cutting the rear cylinder.
• Owners and mechanics have reported rear-cylinder cutout when the engine gets hot.
• But I could not verify from an OEM manual that the 2010 Big Dog Bagger officially includes an intentional overheating protection mode that shuts down the rear cylinder.

Yes. It does look like that. I don't think it is connected to the coil, it is new, bought it a year ago, though I have just bought a new one just in case. In the morning and after the sun set the bike runs perfectly, no issue. It gets hot in the day time over here, +40C (+104F). Summer and September are the hottest months. Harleys run fine though, never had an issue with them in such heat. I am going to ride it in the day time till I get the same symptom, then disconnect the heat sensor and see how it works. I know the controller is locked, confirmed by S&S, so I won't be able to change the settings unless I get a new one.