Snatchy/jerky throttle at low speeds
Discussion
Variable rate throttle reel? https://www.motionpro.com/c/rev3-throttle
"The included cam reel has a progressive profile that allows the throttle to act like a sensitive, long twist throttle during the initial small throttle openings for precise control and then acts like a more aggressive short twist throttle at large throttle openings, progressively shortening the amount of twist needed to reach full throttle"
"The included cam reel has a progressive profile that allows the throttle to act like a sensitive, long twist throttle during the initial small throttle openings for precise control and then acts like a more aggressive short twist throttle at large throttle openings, progressively shortening the amount of twist needed to reach full throttle"
anonymous said:
[redacted]
You could but it won't gain you anything except poor feel.The problem is that at low throttle openings it's running in closed loop and mapped to be very lean for emissions, couple that with the large effect of cracking the throttle slightly and you have a very snatchy response. To fix it you can add fuel at these conditions by remap, maybe replace the throttle for a different cam like the above poster said, or change the gearing to try and move a bit further away from this area.
This is why throttle by wire bikes are much smoother - they have a non-linear map at low openings to help smooth out this transition without meddling with the fuelling.
Krikkit said:
You could but it won't gain you anything except poor feel.
The problem is that at low throttle openings it's running in closed loop and mapped to be very lean for emissions, couple that with the large effect of cracking the throttle slightly and you have a very snatchy response. To fix it you can add fuel at these conditions by remap, maybe replace the throttle for a different cam like the above poster said, or change the gearing to try and move a bit further away from this area.
This is why throttle by wire bikes are much smoother - they have a non-linear map at low openings to help smooth out this transition without meddling with the fuelling.
^What he said The problem is that at low throttle openings it's running in closed loop and mapped to be very lean for emissions, couple that with the large effect of cracking the throttle slightly and you have a very snatchy response. To fix it you can add fuel at these conditions by remap, maybe replace the throttle for a different cam like the above poster said, or change the gearing to try and move a bit further away from this area.
This is why throttle by wire bikes are much smoother - they have a non-linear map at low openings to help smooth out this transition without meddling with the fuelling.
My MT10 had a dreadful jerkiness at low throttle openings. Was awful, i'd start winding the throttle on mid-corner .... nothing...nothing...nothing......40hp.
Had a full days tuning on a rolling road and its loads better. Tuning chap said its all to do with emissions and you could see it on the fuelling graph, very lean at low rpm and minimal throttle. Now its much smoother and makes a bit more power too ! £400 well spent IMO
Krikkit said:
You could but it won't gain you anything except poor feel.
The problem is that at low throttle openings it's running in closed loop and mapped to be very lean for emissions, couple that with the large effect of cracking the throttle slightly and you have a very snatchy response. To fix it you can add fuel at these conditions by remap, maybe replace the throttle for a different cam like the above poster said, or change the gearing to try and move a bit further away from this area.
This is why throttle by wire bikes are much smoother - they have a non-linear map at low openings to help smooth out this transition without meddling with the fuelling.
^What he said The problem is that at low throttle openings it's running in closed loop and mapped to be very lean for emissions, couple that with the large effect of cracking the throttle slightly and you have a very snatchy response. To fix it you can add fuel at these conditions by remap, maybe replace the throttle for a different cam like the above poster said, or change the gearing to try and move a bit further away from this area.
This is why throttle by wire bikes are much smoother - they have a non-linear map at low openings to help smooth out this transition without meddling with the fuelling.
My MT10 had a dreadful jerkiness at low throttle openings. Was awful, i'd start winding the throttle on mid-corner .... nothing...nothing...nothing......40hp.
Had a full days tuning on a rolling road and its loads better. Tuning chap said its all to do with emissions and you could see it on the fuelling graph, very lean at low rpm and minimal throttle. Now its much smoother and makes a bit more power too ! £400 well spent IMO
I find my Ducati can be less than smooth and responsive at low throttle openings when it's not been used much over the last few months.
Putting some extra-expensive petrol through it seems to help. I'm not sure either way whether 'injector cleaner' helps.
Not really sure if the BP 'look at me I can afford it' stuff really matters either, I think the key thing is just to put 500 miles of riding on the clock in few weeks. But using the best petrol which allegedly has more detergent in it seems logical.
My personal theory is injectors get a bit sticky, fouled, lazy, moody.... whatever when left for a while.
Just putting a good amount of petrol through and exercising the injectors helps IMHO.
I do my share of trickling through crap traffic!
Having had a few injectors cleaned by injectortune, I would certainly go this route if a bike didn't run right, before changing anything from 'stock' make sure the 'stock' set up is what it should be. But some bikes do benefit from changing the gearing which is set for passing noise tests. If lots of owners recommend a particular gearing, they may well be right.
Also, if you haven't ridden the bike over winter, the fuel may be a little stale?
The worst thing you can do is fiddle with things to compensate for dirty injectors or stale fuel, because it will be wrong as soon as the clean fuel gets through the system. Obviously a look at the plugs and maybe some new ones never hurt.
Putting some extra-expensive petrol through it seems to help. I'm not sure either way whether 'injector cleaner' helps.
Not really sure if the BP 'look at me I can afford it' stuff really matters either, I think the key thing is just to put 500 miles of riding on the clock in few weeks. But using the best petrol which allegedly has more detergent in it seems logical.
My personal theory is injectors get a bit sticky, fouled, lazy, moody.... whatever when left for a while.
Just putting a good amount of petrol through and exercising the injectors helps IMHO.
I do my share of trickling through crap traffic!
Having had a few injectors cleaned by injectortune, I would certainly go this route if a bike didn't run right, before changing anything from 'stock' make sure the 'stock' set up is what it should be. But some bikes do benefit from changing the gearing which is set for passing noise tests. If lots of owners recommend a particular gearing, they may well be right.
Also, if you haven't ridden the bike over winter, the fuel may be a little stale?
The worst thing you can do is fiddle with things to compensate for dirty injectors or stale fuel, because it will be wrong as soon as the clean fuel gets through the system. Obviously a look at the plugs and maybe some new ones never hurt.
anonymous said:
[redacted]
Get a copy of the service manual, it'll have a procedure for checking the cables.OutInTheShed said:
My personal theory is injectors get a bit sticky, fouled, lazy, moody.... whatever when left for a while.
They don'tEdited by Krikkit on Thursday 16th March 22:22
Krikkit said:
[q....
Well, that's your opinion, mine is based on a) putting injectors on a test rig and seeing what happens, and b) riding V twins in traffic.OutInTheShed said:
My personal theory is injectors get a bit sticky, fouled, lazy, moody.... whatever when left for a while.
They don'tEdited by Krikkit on Thursday 16th March 22:22
If your bike isn't as smooth and responsive as it used to be at small throttle openings, something has changed.
To be fair, there is probably an element of 'you get used to it' once you've done 1000 miles on a bike in a couple of months.
But swapping from a frequently used bike to one that's been laid up for the winter tells a tale.
Another thing to consider is the stuff that accumulates in all the other components of an EFI system, filters, pump, hoses, pressure regulator.
EFI bikes are a lot better than carbs, but they still need a bit of care now and then.
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