More Snatchy Throttle Stuff and a Cure
Here is a link to the GSXS Thread about Snatchy Throttle and my response and cure:
https://www.gsxs1000.org/threads/snatchy-throttle-issue-fixed.42028/page-12#post-398682
There is some confusion here. There are 2 issues being discussed. One is the snatchy throttle and the other is surging and poor fueling at low throttle opening. They are 2 different things which require 2 different fixes.
There is also some confusion over the generic term "flashing". When you flash an ECU there are about 50 options you can play with. These include changing the fuel mapping, switching off various functions, changing idle rpm, changing the fan temp switch and so on. When you get your ECU flashed, it is essential to know what to ask for or at least know what the shop is going to change.
Using the Woolich Racing Tuning software, the most effective option, to improve the bike, (we are not talking about more HP) is to disable the Deceleration Fuel Cut. This completely eliminates the on off snatching, as it stops the ECU from completely shutting off the fuel when you close the throttle 100%. Doing this one thing (it takes less than 30 seconds to do) will transform your bike. You could, almost, only do this and forget about everything else as this will have cured the most annoying glitch. You would still have some poor fueling at low throttle cruising and a bit of a hole in the power band. But if you ride your bike hard most of the time and don't do long stretches of highway cruising, you would be fine.
If however, you do a lot of slower riding and cruising and you want to improve the hunting/surging, then the next thing to do is to eliminate the poor fueling at lower throttle openings, which is particularly noticeable at lower cruising speeds. The closed loop system in use on this bike, with it's narrow band O2 sensor, will be trying to reduce harmful emissions, by running the bike as lean as possible.
When I have tested my bike (2019 model) under these conditions, I have seen the AFR go as lean as 16:1. At this point the engine is starved of fuel, runs like a bag of shite and is constantly hunting/surging. Unfortunately the narrow band O2 sensor is basically an on/off switch, telling the ECU when the fueling is not optimum, rather than a wideband O2 sensor, that has a variable voltage output and can tell the ECU by how much the fueling is off. This leads to this on/off surging/hunting problem. It was the cheap option.
Now as far as I know, is isn't actually possible to turn OFF the O2 sensor by flashing (it certainly isn't on the Woolich Racing software) so the only real option is to physically remove the O2 sensor from the exhaust and cap the hole with a bung. This leaves you with an issue. Firstly the ECU will put up an F1 code. When you interrogate the ECU to determine what is causing the F1 code it shows up 2 problems; one is that the O2 heater is shorted to ground or open and the other is that the O2 sensor is not activated. Both obviously as a result of the O2 sensor being removed. The Woolich Racing software does have an option to address this as shown below:
You simply disable the Stock O2 Sensor F1 code. This solves the problem and the F1 light goes away. This is not the same as disabling the O2 sensor in the ECU, which is something I don't think you can do. The only way to disable it, is to remove it physically from the bike. I am unsure as to how this effects the operation of the ECU but it is most likely that the ECU now assumes that the AFR is OK and stops trying to switch the fuel on and off to reduce emissions.
Either way, removing the O2 sensor and disabling the Sensor F1 code will certainly help with fueling and reduce some of the surging.
The other option, as has been discussed on this thread, is to use an O2 eliminator/optimiser dongle thingy. You can leave the O2 sensor in the exhaust system or remove it and put a bung in the hole. Either way, you will disconnect the O2 sensor cable (under the fuel tank near the throttle bodies on the left hand side) and in it's place, put one of those little eliminator devices. As I understand it, they simply send a signal to the ECU, telling it that all is well with the O2 sensor and that the fueling does not need any adjustment. So again, it eliminates the hunting/surging when cruising at low throttle opening. Depending on the ECU that you have (pre-2017 or 2017-2019), you may find that using this method will cause the F1 light to come up again with the resultant irritation of having the Trip meters and MPG figures being messed up. The O2 eliminator does not cure snatchy throttle but it may mask it a little. The only way to cure snatchy throttle is to disable the Deceleration Fuel Cut
I do believe that the modifications to the 2017-2019 ECU, which resulted is slightly better fueling and a reduction in this hunting/surging, (but did nothing to eliminate the snatchy throttle) were primarily in this area of messing around with the closed loop narrow band O2 sensor and what it told the ECU. It resulted in better fueling in the cruising at low throttle but left most people still dissatisfied with the overall feel of the bike.
There is some confusion here. There are 2 issues being discussed. One is the snatchy throttle and the other is surging and poor fueling at low throttle opening. They are 2 different things which require 2 different fixes.
There is also some confusion over the generic term "flashing". When you flash an ECU there are about 50 options you can play with. These include changing the fuel mapping, switching off various functions, changing idle rpm, changing the fan temp switch and so on. When you get your ECU flashed, it is essential to know what to ask for or at least know what the shop is going to change.
Using the Woolich Racing Tuning software, the most effective option, to improve the bike, (we are not talking about more HP) is to disable the Deceleration Fuel Cut. This completely eliminates the on off snatching, as it stops the ECU from completely shutting off the fuel when you close the throttle 100%. Doing this one thing (it takes less than 30 seconds to do) will transform your bike. You could, almost, only do this and forget about everything else as this will have cured the most annoying glitch. You would still have some poor fueling at low throttle cruising and a bit of a hole in the power band. But if you ride your bike hard most of the time and don't do long stretches of highway cruising, you would be fine.
If however, you do a lot of slower riding and cruising and you want to improve the hunting/surging, then the next thing to do is to eliminate the poor fueling at lower throttle openings, which is particularly noticeable at lower cruising speeds. The closed loop system in use on this bike, with it's narrow band O2 sensor, will be trying to reduce harmful emissions, by running the bike as lean as possible.
When I have tested my bike (2019 model) under these conditions, I have seen the AFR go as lean as 16:1. At this point the engine is starved of fuel, runs like a bag of shite and is constantly hunting/surging. Unfortunately the narrow band O2 sensor is basically an on/off switch, telling the ECU when the fueling is not optimum, rather than a wideband O2 sensor, that has a variable voltage output and can tell the ECU by how much the fueling is off. This leads to this on/off surging/hunting problem. It was the cheap option.
Now as far as I know, is isn't actually possible to turn OFF the O2 sensor by flashing (it certainly isn't on the Woolich Racing software) so the only real option is to physically remove the O2 sensor from the exhaust and cap the hole with a bung. This leaves you with an issue. Firstly the ECU will put up an F1 code. When you interrogate the ECU to determine what is causing the F1 code it shows up 2 problems; one is that the O2 heater is shorted to ground or open and the other is that the O2 sensor is not activated. Both obviously as a result of the O2 sensor being removed. The Woolich Racing software does have an option to address this as shown below:
You simply disable the Stock O2 Sensor F1 code. This solves the problem and the F1 light goes away. This is not the same as disabling the O2 sensor in the ECU, which is something I don't think you can do. The only way to disable it, is to remove it physically from the bike. I am unsure as to how this effects the operation of the ECU but it is most likely that the ECU now assumes that the AFR is OK and stops trying to switch the fuel on and off to reduce emissions.
Either way, removing the O2 sensor and disabling the Sensor F1 code will certainly help with fueling and reduce some of the surging.
The other option, as has been discussed on this thread, is to use an O2 eliminator/optimiser dongle thingy. You can leave the O2 sensor in the exhaust system or remove it and put a bung in the hole. Either way, you will disconnect the O2 sensor cable (under the fuel tank near the throttle bodies on the left hand side) and in it's place, put one of those little eliminator devices. As I understand it, they simply send a signal to the ECU, telling it that all is well with the O2 sensor and that the fueling does not need any adjustment. So again, it eliminates the hunting/surging when cruising at low throttle opening. Depending on the ECU that you have (pre-2017 or 2017-2019), you may find that using this method will cause the F1 light to come up again with the resultant irritation of having the Trip meters and MPG figures being messed up. The O2 eliminator does not cure snatchy throttle but it may mask it a little. The only way to cure snatchy throttle is to disable the Deceleration Fuel Cut
I do believe that the modifications to the 2017-2019 ECU, which resulted is slightly better fueling and a reduction in this hunting/surging, (but did nothing to eliminate the snatchy throttle) were primarily in this area of messing around with the closed loop narrow band O2 sensor and what it told the ECU. It resulted in better fueling in the cruising at low throttle but left most people still dissatisfied with the overall feel of the bike.
Good information. Any new information to share? Nothing posted since last year's end.
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