Jerky at 30-50 km/h

[THOR]

Hi THOR.
Thanks for your answer. You’re the only one except me (so far) having the same problem. Interesting. Have you complained at your dealer, and if, what did he answer?

i didn't as i know dealers, they have got no clue usually. The bike does this and any dealer will say this bike should do that but this is not normal. The bike has been restricted so much that it runs very very lean. i am sure as soon as you remove the emission devices the bike will be very good.

its definitely O2 sensors, and also very lean mapping. Nothing to worry about it is fixable.

[JonTheChron]

i have the same problem, but it must be something to do with emission regulations, O2 sensors are not wideband so i agree they might cause this, but i also think its the fuel injector deceleration cut is very powerful. I almost feel like the bike wants to throw me from on top of it.

I felt the same when my bike was new, I don't feel it anymore though.

[THOR]

i have the same problem, but it must be something to do with emission regulations, O2 sensors are not wideband so i agree they might cause this, but i also think its the fuel injector deceleration cut is very powerful. I almost feel like the bike wants to throw me from on top of it.

I felt the same when my bike was new, I don't feel it anymore though.

yes but my bike has 1890 miles on it, so its not so new

[Galbert]

Thanks JonTheChron.
I felt this problem “at once” and mentioned it at the 1000 km service. Of course the dealer “couldn’t do anything”. I thought it might be better after breaking in, but unfortunately not. It’s now over 6000 km on the meter, and no difference.
“THOR” says something very interesting: “as soon as you remove the emission devices the bike will be very good. ”. Is that a difficult thing to do?

[Champ87]

“THOR” says something very interesting: “as soon as you remove the emission devices the bike will be very good. ”. Is that a difficult thing to do?

No, not difficult. Vcyclenut previously mentioned that you could have a bad O2 sensor so that's the obvious point to start. To disable the O2 sensor you can simply disconnect the wires. That will prevent the bike running in closed-loop mode (where the ECU adjusts fueling based on readings from the O2 sensor). If you do that you will get a yellow check engine light and the ECU will store an error code. You'll be able to clear the error code when you reconnect the O2 sensor. If disconnecting the O2 sensor improves low-speed running then you can permanently disable the error using software to access the ECU.

The next step would be fuel mapping. When THOR says the bike runs lean that is a very broad statement that doesn't bear out when you look at the fuel maps. There are areas where the bike runs lean but also many rpm/throttle combinations where fuel can be reduced for best performance. Whether it runs rich or lean, the solution is the same - revised mapping by an experienced tuner. You could either buy a preconfigured map from someone like vcyclenut or pay a tuner to develop a custom tune running your bike on a dyno. In each case the tuner will remove the throttle restrictions and release a significant amount of extra power once the fueling is adjusted to suit.

Some people like to install block off plates and remove the secondary air injection. This system introduces air into the exhaust but it happens after combustion so it will not affect power or the way your bike runs. Removing the system can reduce exhaust temperature and there is a slight reduction in weight. It's not going to solve your issues but I mention it so you don't get misled.

Bear in mind that there are plenty of owners with completely stock bikes who are not suffering the same issues. Disabling/removing some devices may cure your bike but it's also possible that your bike has an unrelated issue that requires a different solution. Keep your mind open.

[cOoTeR]

“THOR” says something very interesting: “as soon as you remove the emission devices the bike will be very good. ”. Is that a difficult thing to do?

No, not difficult. Vcyclenut previously mentioned that you could have a bad O2 sensor so that's the obvious point to start. To disable the O2 sensor you can simply disconnect the wires. That will prevent the bike running in closed-loop mode (where the ECU adjusts fueling based on readings from the O2 sensor). If you do that you will get a yellow check engine light and the ECU will store an error code. You'll be able to clear the error code when you reconnect the O2 sensor. If disconnecting the O2 sensor improves low-speed running then you can permanently disable the error using software to access the ECU.

The next step would be fuel mapping. When THOR says the bike runs lean that is a very broad statement that doesn't bear out when you look at the fuel maps. There are areas where the bike runs lean but also many rpm/throttle combinations where fuel can be reduced for best performance. Whether it runs rich or lean, the solution is the same - revised mapping by an experienced tuner. You could either buy a preconfigured map from someone like vcyclenut or pay a tuner to develop a custom tune running your bike on a dyno. In each case the tuner will remove the throttle restrictions and release a significant amount of extra power once the fueling is adjusted to suit.

Some people like to install block off plates and remove the secondary air injection. This system introduces air into the exhaust but it happens after combustion so it will not affect power or the way you bike runs. Removing the system can reduce exhaust temperature and there is a slight reduction in weight. It's not going to solve your issues but I mention it so you don't get misled.

Bear in mind that there are plenty of owners with completely stock bikes who are not suffering the same issues. Disabling/removing some devices may cure your bike but it's also possible that your bike has an unrelated issue that requires a different solution. Keep your mind open.

Will disconnecting the 02 sensor without blocking the fault code send the bike into limp mode (reduced power mode)?

If you are going to do the dyno tune route you will need to either install the block off plates or have a tuner that knows where and how to pinch off the secondary injection system. Also if you install an aftermarket exhaust it may cause popping noises when you let off the throttle if you don't install block off plates.

[Champ87]

Will disconnecting the 02 sensor without blocking the fault code send the bike into limp mode (reduced power mode)?

That's a question I can't answer for sure. Removing or disabling the O2 sensor will not harm the engine so there is no need for it to go into safe mode.

For Galbert it's definitely worth a try - a simple cheap way to see if the O2 sensor is part of the problem. If it doesn't improve things then simply reconnect and cross it off the list.

[Galbert]

Hi all.
I really appreciate all tips and tricks. I have started lifting the tank today, but unfortunately I ran out of time. I spent a little too much time trying to separate the O2 sensor connector without lifting the tank, but it seems impossible.
I’ll let you know the result when the test is done.

[Galbert]

Hi again.
O2 sensor disconnected. Engine starts up as normal. No ECU light at idling. Unfortunately the weather from Silverstone yesterday is in Sweden today, so there will be no test ride. You’ll hear from me as soon as the test is done.
Very exiting!

[THOR]

Hi again.
O2 sensor disconnected. Engine starts up as normal. No ECU light at idling. Unfortunately the weather from Silverstone yesterday is in Sweden today, so there will be no test ride. You’ll hear from me as soon as the test is done.
Very exiting!

no engine Fault light after removing O2 sensors ? are you sure you definitely disconnect the correct thing? If you did wow thats great then i am removing mine tomorrow first thing
do you need to remove the tank?