Rev Limit at 5,500 RPM

[wanobiben_imp]

Just so you know, the bike has a bidirectional serial data line between the ECU and the Combination Meter. (2010-13 bikes do not have this)

The meter sends to the ECU: Rear wheel speed sensor signal

The ECU sends to the meter: High oil temperature indicator signal, Engine speed signal, MIL signal, Fuel pulse signal.

Do you think that there’s a way I could rewire the rear speed sensor to the ECU directly, or does the meter sort of translate the speed sensor reading into data the ECU can understand?

[Lord Popgun]

Like mentioned in an above post, the OEM sensor is reading (or actually making) pulses from the slotted ring. So there are a lot of pulses going to the meter. And you can see the pulses from the sensor with an o-scope. I have done that and posted a video of them on youtube. They are just square waves whose freq. varies with wheel speed.

The signal on a serial data line will have some sort of word format as it is a digital communication between the two devices. We have no information on that format or how to interpret it. It could be a CANBUS type but I don't know.

So no, you can't just fire pulses from your speed sensor into the ECU (maybe yes on a 2010-13). Even if you could you would only be getting one pulse per wheel revolution instead of the more numerous pulses the pulser ring provides and speed data would be incorrect into the ECU.

I would imagine your new meter takes the speed data and encodes it into the word going to the ECU. And some setup on your new meter is incorrect or not compatible with the Honda.

I went to the US website for your meter and could not find that model. Maybe you could call them for more info.

[Lord Popgun]

That would depend on the model year. The 2010-2013 ECU is not compatible with any later year. After that, maybe. Some research would have to be done. Like checking the part numbers for one.

[wanobiben_imp]

Two questions come to my mind,
why did you change the gauge ?
when you say speedometer, you’re referring to the rpm gauge, right ?
or did you replace both “clocks” ?

I changed it to have a lower profile overall on the bike. I don't like the way the stock gauge sticks out so much. I went with a digital one as it has the smallest profile over any of the dials I've seen. I replaced the whole stock unit with an all in one digital tach/speedo/fuel gauge/gear indicator.

That would depend on the model year. The 2010-2013 ECU is not compatible with any later year. After that, maybe. Some research would have to be done. Like checking the part numbers for one.

I have a 2014 CB1100, no ABS or EX just the base model.
These are before and after pictures to show how much lower the profile is of the new meter vs the stock. Before:
After, with new meter:

Like mentioned in an above post, the OEM sensor is reading (or actually making) pulses from the slotted ring. So there are a lot of pulses going to the meter. And you can see the pulses from the sensor with an o-scope. I have done that and posted a video of them on youtube. They are just square waves whose freq. varies with wheel speed.

The signal on a serial data line will have some sort of word format as it is a digital communication between the two devices. We have no information on that format or how to interpret it. It could be a CANBUS type but I don't know.

So no, you can't just fire pulses from your speed sensor into the ECU (maybe yes on a 2010-13). Even if you could you would only be getting one pulse per wheel revolution instead of the more numerous pulses the pulser ring provides and speed data would be incorrect into the ECU.

I would imagine your new meter takes the speed data and encodes it into the word going to the ECU. And some setup on your new meter is incorrect or not compatible with the Honda.

I went to the US website for your meter and could not find that model. Maybe you could call them for more info.

I bought it off of [url=https://www.ebay.com/itm/304200414290]ebay. There are no brand names mentioned on the seller's listing. The only videos I could find of it on youtube were in some other language, but on their post they called it a [url=https://youtu.be/mHj7ywknCso]KOSO RX4N. I looked at [url=https://kosonorthamerica.com/product-category/meters/multifunction/]KOSO's website and couldn't find anything that looked similar.

[Randy B]

Something just occurred to me... these motorcycles use a waste spark system where there are 2 coils for the 4 spark plugs. Meaning that the coils fire twice as many times as needed for the number of cylinders. I wonder if changing the number of cylinders to 8 would make a difference?
I could be WAY off base here, but what could it hurt?

[Lord Popgun]

Randy, that is a good idea and an easy thing to try.

[wanobiben_imp]

Something just occurred to me... these motorcycles use a waste spark system where there are 2 coils for the 4 spark plugs. Meaning that the coils fire twice as many times as needed for the number of cylinders. I wonder if changing the number of cylinders to 8 would make a difference?
I could be WAY off base here, but what could it hurt?

Thanks for the suggestion, but I can only adjust it for 1,2 and 4 cylinders.

After doing a lot more digging on this forum, and I think someone may have mentioned it on my thread, I think the problem is in my ECU. Since changing out the meter I had to install a magnetic speed sensor on the front wheel. That means that the original optical speed sensor on the back wheel is no longer in use. I’ve read something about the original speed sensor communicating with the original speedo and that speedo translating the speed back to the ECU to keep the bike from going over its 110mph limit. Since the original speed sensor is no linger communicating to the ECU there is likely a fail safe that keeps the bike from going above 5,000rpm, because at 5,000rpm in 6th gear (don’t have proof, only estimating) might take you past 110mph which the bike is not made to handle.

I think my only hope for using this aftermarket speedo is to have a local shop reflash my ECU to release that fail safe and maybe set a new parameter somehow. But, the likelihood of them doing that is very slim as that ends up being a liability for them by trusting me to not go over that 110mph cap with the rev limits removed.

I think my only options now are to 1) live with the 5,000rpm limit, 2) reinstall the original speedometer, or 3) find a speedometer that will be able to use the original speed sensor and will communicate with the ECU. I’m afraid option 2 is the most practical, but I can’t stand the way it looks with the modifications I’ve already done to the bike.

[Lord Popgun]

Just so ya know, the OEM speed sensor is not optical. It is a Hall effect sensor.

[Cormanus]

wanobiben, three things.

First, I’m not sure there is any problem with the bike exceeding 112 mph (180 kph). My understanding is that the speed limiter is a requirement of Japanese law and for some reason Honda have left it in place on exported bikes.

Second, on the basis of the information on this forum, the only place (maybe in the world) that’s ever reflashed the CB1100’s ECU is Don Guhl motors and he will no longer do it for legal reasons. Search the forum if you’re interested; there’s discussion about it somewhere.

Third, is there someway to fudge it and fool the ECU into believing the original speedo is still attached? Or even reconnect it and hide it under the seat somewhere?

[wanobiben_imp]

wanobiben, three things.

First, I’m not sure there is any problem with the bike exceeding 112 mph (180 kph). My understanding is that the speed limiter is a requirement of Japanese law and for some reason Honda have left it in place on exported bikes.

Second, on the basis of the information on this forum, the only place (maybe in the world) that’s ever reflashed the CB1100’s ECU is Don Guhl motors and he will no longer do it for legal reasons. Search the forum if you’re interested; there’s discussion about it somewhere.

Third, is there someway to fudge it and fool the ECU into believing the original speedo is still attached? Or even reconnect it and hide it under the seat somewhere?

Today I’ve actually been thinking about buying a used stock speedo and taking it apart to fit under the seat. It may end up being the easiest solution without just reinstalling the original speedo.