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Discussion Starter · #1 ·
If anyone has been following my posts on the surging hesitation issue, they will know that I love the Africa Twin but have spent a fortune in time and money trying to solve the ONLY minor gripe I have with the bike - the surging and hesitation when you are trying to ride at a steady speed slowly through town.
I've tried PowerCommanders, Rapid Bike Easy, and RapidBike Evo none of which made any difference ...... But the other day I poured a whole bottle of fuel injector cleaner into the 10 litres of fuel that were in my tank and rode it until it was nearly dry (about 80 miles)
And I think it's worked. Where previously I would have given the bike a 3 out of 10 for slow urban riding, I'd say it's now almost on par with my Thruxton at about 7 out of 10, and I think most of the rest of the 30% is down to the DCT box which Honda seem to have addressed with the latest 2022 incarnation (mine's a 2019 so no chance of getting updated firmware).
There's more to say (not least how brand-new bikes with this problem could possibly have dirty fuel injectors), but I will expand on the idea if people show interest in this thread.
Mike
 

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Discussion Starter · #5 ·
Good point DT, but I think I have seen posts by manual owners complaining about the issue. I suspect that since they can more easily choose the gear they are going to use for say 28mph they may often change down to 3rd and the problem diminishes.
Mike
 

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Good point DT, but I think I have seen posts by manual owners complaining about the issue. I suspect that since they can more easily choose the gear they are going to use for say 28mph they may often change down to 3rd and the problem diminishes.
Mike
I believe I have read about it at least once too.
 

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Discussion Starter · #8 ·
I have a manual and it surges with realy low RPM, I always though that it's the ECU fault and a tune will fix it, definitely trying this solution.
Just something to bear in mind - the instructions on a typical bottle suggest putting it in a full car tank. IMHO this would be much too dilute. The bottle I used was about 200cc and it went in about 10 litres of fuel.
Mike
 

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If anyone has been following my posts on the surging hesitation issue, they will know that I love the Africa Twin but have spent a fortune in time and money trying to solve the ONLY minor gripe I have with the bike - the surging and hesitation when you are trying to ride at a steady speed slowly through town.
I've tried PowerCommanders, Rapid Bike Easy, and RapidBike Evo none of which made any difference ...... But the other day I poured a whole bottle of fuel injector cleaner into the 10 litres of fuel that were in my tank and rode it until it was nearly dry (about 80 miles)
And I think it's worked. Where previously I would have given the bike a 3 out of 10 for slow urban riding, I'd say it's now almost on par with my Thruxton at about 7 out of 10, and I think most of the rest of the 30% is down to the DCT box which Honda seem to have addressed with the latest 2022 incarnation (mine's a 2019 so no chance of getting updated firmware).
There's more to say (not least how brand-new bikes with this problem could possibly have dirty fuel injectors), but I will expand on the idea if people show interest in this thread.
Mike
I’ve played around with fuel additives also. Something to consider is when it’s mixed pretty rich its burn rate being different than gasoline may be positively effecting performance. If your bike returns to crummy performance when you stop using the additive then your injectors weren’t dirty, your bike just likes the mixture you concocted.
 

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Discussion Starter · #10 ·
I’ve played around with fuel additives also. Something to consider is when it’s mixed pretty rich its burn rate being different than gasoline may be positively effecting performance. If your bike returns to crummy performance when you stop using the additive then your injectors weren’t dirty, your bike just likes the mixture you concocted.
Yes I wondered about that being a problem. But I ran the fuel+additive tank down to just 2 litres left in the tank, then filled up with 17 litres of new fuel, so I am hoping the residual injector cleaner will now be very minimal. Also at first (the first 20 miles or so) with the additive in the 10 litres of fuel felt no different from normal (ie not nice around town) but by the time I had done 80 miles it was much better.
Mike
 

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Having an 18 ATAS with the fuel tank recall flaking issues, I picked up a set of used low mileage (3K miles, also off an 18 ATAS) throttle bodies for the fuel injectors and sent them out to be flow tested and cleaned to swap with my original injectors. The injectors tested marginal, cleaned and tested again with good results. I swapped the injectors when servicing my bike at 10K and also installed Rapid Bike Racing with PAIR valve removal & block off. I've already replaced the fuel filter assembly and fuel pump strainer a few times and run a Guglatech fuel pump filter sock and the filler neck filter. Added a half bottle of Liqui Moly Jectron fuel injector cleaner to the tank with fresh fuel and with the RB full system base map + auto-adaptive tuning, by bike has never run better in the 1500 miles since. With how much debris was in my fuel tank when I checked and cleaned, I always suspected the injectors were not performing optimally with the poor rideability and stalling and something I feel Honda hasn't properly addressed with the recall. I'll be doing a bit more tuning with the RB here soon and building a second map for fuel economy.
 

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Discussion Starter · #12 ·
Having an 18 ATAS with the fuel tank recall flaking issues, I picked up a set of used low mileage (3K miles) throttle bodies for the fuel injectors and sent them out to be flow tested and cleaned to swap with my original injectors. The injectors tested marginal, cleaned and tested again with good results. I swapped the injectors when servicing my bike at 10K and also installed Rapid Bike Racing with PAIR valve removal & block off. I've already replaced the fuel filter assembly and fuel pump strainer a few times and run a Guglatech fuel pump filter sock and the filler neck filter. Added a half bottle of Liqui Moly Jectron fuel injector cleaner to the tank with fresh fuel and with the RB full system base map + auto-adaptive tuning, by bike has never run better in the 1500 miles since. With how much debris was in my fuel tank when I checked and cleaned, I always suspected the injectors were not performing optimally with the poor rideability and stalling and something I feel Honda hasn't properly addressed with the recall. I'll be doing a bit more tuning with the RB here soon and building a second map for fuel economy.
For the record though …. My bike is a standard crf1000l and as such has never had the tank debris problem that was only associated with the bigger tanks I believe. But it’s still interesting that your second hand injectors tested ‘marginal’ even at just 3k miles.
Mike
 

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Never could relate to any throttle response problems with my AT. Other bikes, yes. Like my former Z1000 was probably the worst and had an easy solution with a throttle position sensor adjustment.

My AT frequently gets fuel system cleaner and the fuel I keep in the garage has Sta-bil. Often, I skip the station top-off before getting to the house and use the fuel jug in the garage.

No performance mods to my AT.
 

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What RPMs are we talking here? I actually short-shift in town to tone down the ridiculous engine braking. I'll run in 3rd at 1500 rpms on flat ground.
 

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For the record though …. My bike is a standard crf1000l and as such has never had the tank debris problem that was only associated with the bigger tanks I believe. But it’s still interesting that your second hand injectors tested ‘marginal’ even at just 3k miles.
Mike
Edited my post to mention that the injectors were also from an 18 ATAS so was curious how they'd test and I'll send in my original injectors for testing and cleaning eventually.
 

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What RPMs are we talking here? I actually short-shift in town to tone down the ridiculous engine braking. I'll run in 3rd at 1500 rpms on flat ground.
User 1 is set for around town for me: power turned all the way down, engine braking turned all the way down and wheelie control and traction control turned all the way up. Low speed manners are decent, short shifting into second and third definitely helps. 2022 CRF1100A.
 

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Discussion Starter · #17 ·
with great respect to a couple of the posters above, different ways of riding the bike to get round the engine problem that some bikes have, has been explored in other threads and yes it can make matters easier (ie mask the issue). My technique was to use gravel mode (least engine braking and least power). This helps a bit on bumpy roads but doesn't solve the problem of trying to ride smoothly on flat or downhill roads with virtually no throttle.
 

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Discussion Starter · #18 ·
If anyone has been following my posts on the surging hesitation issue, they will know that I love the Africa Twin but have spent a fortune in time and money trying to solve the ONLY minor gripe I have with the bike - the surging and hesitation when you are trying to ride at a steady speed slowly through town.
I've tried PowerCommanders, Rapid Bike Easy, and RapidBike Evo none of which made any difference ...... But the other day I poured a whole bottle of fuel injector cleaner into the 10 litres of fuel that were in my tank and rode it until it was nearly dry (about 80 miles)
And I think it's worked. Where previously I would have given the bike a 3 out of 10 for slow urban riding, I'd say it's now almost on par with my Thruxton at about 7 out of 10, and I think most of the rest of the 30% is down to the DCT box which Honda seem to have addressed with the latest 2022 incarnation (mine's a 2019 so no chance of getting updated firmware).
There's more to say (not least how brand-new bikes with this problem could possibly have dirty fuel injectors), but I will expand on the idea if people show interest in this thread.
Mike
.... so there DOES indeed seem to be some interest in this idea, and perhaps others can try it and report back their results. I will of course report back if mine reverts fairly quickly to poor engine behaviour.
In the meantime here are some other points in no particular order:
  • If gummed up fuel injectors are the problem, how come some brand new bikes have the surging hesitation issue (I have ridden 3 demonstrators that all had it)
  • Why do no bike manufacturers include injector cleaning in maintenance schedules (or do they)?
  • I had assumed that since the bike was running much better, the uneven idle would have improved but it hasn't.
  • I did notice though that the bike trundles along much faster on a closed throttle (DCT remember) than it had been doing
  • My fuel consumption seems to have improved by about 7%, but it's very difficult to judge because I may have been riding more gently to test the 'repair'
  • I haven't noticed any change in the engine braking behaviour - it still seems too fierce most of the time, but I will do some more detailed experiments.
Mike
 

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.... so there DOES indeed seem to be some interest in this idea, and perhaps others can try it and report back their results. I will of course report back if mine reverts fairly quickly to poor engine behaviour.
In the meantime here are some other points in no particular order:
  • If gummed up fuel injectors are the problem, how come some brand new bikes have the surging hesitation issue (I have ridden 3 demonstrators that all had it)
  • Why do no bike manufacturers include injector cleaning in maintenance schedules (or do they)?
  • I had assumed that since the bike was running much better, the uneven idle would have improved but it hasn't.
  • I did notice though that the bike trundles along much faster on a closed throttle (DCT remember) than it had been doing
  • My fuel consumption seems to have improved by about 7%, but it's very difficult to judge because I may have been riding more gently to test the 'repair'
  • I haven't noticed any change in the engine braking behaviour - it still seems too fierce most of the time, but I will do some more detailed experiments.
Mike
I've encountered the issue of surging, or as we called it "hunting", with a couple models. In those circumstances the issue could be traced back to the engine management unit using injector duration to try to get the voltage it wanted to see from the oxygen sensor in the exhaust. With one model the problem was caused by air leaking past the rubber boot that the throttle valve slips into on the intake side of the cylinder head. This is very common on bikes that have some miles on them. The rubber boots shrink over time. That was easy to fix, simply snug up the clamp around the boot. The diagnostic was to shoot some brake cleaner around the edge of the boot where it meets the throttle valve with the engine running. CAUTION: use brake cleaner, not carb cleaner. Carb cleaner will damage paint! If there is any perceivable change to the idle, the boot is leaking and the clamp needs to be tightened or the boot replaced. Let the engine reach operating temperature before performing diag. On my 2022 AT, the clamps are accessible without removing any bodywork. In addition, there may be some benefit to slightly loosening and retorquing the nuts that secure the exhaust clamps to the cylinder head. Again, it the exhaust gaskets compress under the pressure of the nuts through repeated heating/cooling cycles, air can leak past the gaskets and cause the oxygen sensors to generate a funky signal. The other issue we encountered was that the throttle valves were pulling different amounts of vacuum at small throttle openings. To diagnose that would require accessing the linkage between the two valves and the use of VERY sensitive equipment for measuring vacuum. If I were experiencing this issue, I would start with checking for leaks and then go from there. Hope this helps.
 

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I believe that the only cause of this problem is the programming of how the gears change at certain speeds.
1st gear switch to 2nd at 23 km per hour.
If the throttle is slightly open the 1st gear has the tendency to hang around the 23km limit and not change to the 2nd with ease.
23 km is too high. When I slow down to turn right or left, the bike always switch to 1st gear because the speeds drops just shy of the 23km mark.
Then you accelerate and immediately switches to 2nd. The funny thing is that you cannot switch to 2nd gear manually with the buttons. It allows you with all the other gears EXCEPT the first.
So when I ride in the traffic I always use manual mode so I can switch to 2nd gear at 17km and enjoy a smooth transition to the 2nd and acceleration.
So HONDA MUST fix these two things.
To be able to switch to the 2nd gear in Drive mode wherever you wish above 10km and the 23km mark to become 20 or slightly below.
 
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