Question TRYING to solve the snatchy throttle

Morelius

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Hello everyone. Here comes another individual afflicted by the snatchy throttle. How's it going, Piggy? Any updates?

I'm going to share my information and see if, together, we can find a solution.

I recently acquired a PC3, and today I've been experimenting with it for 400 km. I've tried enriching and leaning out the mixture in RPM ranges from 2000 to 7000 and throttle position 2 to 10%. There have been some sweet moments, but as I've covered more kilometers, that characteristic throttle kick has reappeared. I think I've read on this forum about a user who contacted Dynojet and was advised to disconnect the O2 sensor. I've also read this advice from Ivan of Ivan's Performance Products. It makes sense since the ECU continuously updates its tables based on feedback received from the sensor. In this case, the PC3 is only a parasite that adds +x% of fuel, so it's logical to think that if the ECU receives a signal of a very rich mixture through the O2 sensor, it might end up leaning out the mixture.

I would like to perform the battery disconnect test to reset the ECU, disconnect the O2 sensor, load a new map, and try again.

So far, the only things that have slightly alleviated the issue are increasing the idle speed (around 1400 rpm) and adjusting the throttle cable slack. However, all of this only marginally softens the throttle kick but nowhere near enough.

All being said, I love the bike, but this flaw completely ruins the overall riding experience.
 
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TownsendsFJR1300

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No, anytime I change gears. I let off the throttle to shift, after shifting it won't let me slowly roll into the throttle. I can probably explain it better with an analogy. Say the throttle goes in increments of 0-10. Zero being idle & 10 being WOT. I feel like mine goes from 0-2 or 3 instantly. Hope that makes better sense.

That's pretty normal for this bike.

It takes quite some seat time to shift W/O what your describing.
I normally shift around 4K. Rarely do I go above 8K. It seems to shift better at higher RPMs,
with much less of what you describe.

With that said, once rolling, I'll sometimes clutch-less shift just matching speed to RPMs.
Sounds and feels like an automatic if done correctly...

.
 

Morelius

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This is not how the fuel/ignition map works in the FZ6 ECU. It is closed loop, relying on look up tables.
You mean it switches from one kind of internal table to another when in closed loop operation depending on the O2 sensor readings? If this is the case still makes sense to unplug the O2 sensor to force the ecu operate only in open loop? Am I right?
 

Gary in NJ

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A disconnected O2 sensor is a failure condition where it reverts to a fixed value on the table - and displays a failure code on the instrument cluster. While the bike is ridable, horsepower is restricted.

Better to solve the actual problem than to create work-arounds.

Can you post a video of the condition you experience with the bike in neutral on the stand? Just get video of you turning the throttle. Be sure to show the free play prior to starting the engine. Just get the throttle, if the video has audio I don’t need to see the tach, I’ll hear it. Move the throttle as slowly as you can.
 

Morelius

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A disconnected O2 sensor is a failure condition where it reverts to a fixed value on the table - and displays a failure code on the instrument cluster. While the bike is ridable, horsepower is restricted.

Better to solve the actual problem than to create work-arounds.

Can you post a video of the condition you experience with the bike in neutral on the stand? Just get video of you turning the throttle. Be sure to show the free play prior to starting the engine. Just get the throttle, if the video has audio I don’t need to see the tach, I’ll hear it. Move the throttle as slowly as you can.

I'll be out of house for a week but when i come back I may try to do a video. What are you looking for with this video? I don't have any issue in neutral, neither with idle or throttle slack. The condition I experience is exactly the same as piggy in his OP video (super clear around 1:30). It's the very same problem: a kind of power lag after opening the throttle, no matter how smoth or slowly you do it. You always have a delayed kick after openning the throttle. If you open the throttle super smothly or slowly the kick is maybe a little bit softer but its always there. Much more noticeable in 2nd, 3rd an 4th gear specially after deceleration.
 
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Gary in NJ

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I want to see how the engine reacts to small throttle inputs. I want to see the amount of free play available.

If the engine has “normal” reaction while in neutral, then there is absolutely no reason it shouldn’t be the same while riding. It’s not a ride by wire system, it’s a mechanical connection between throttle and throttle bodies.

The EFI isn’t speed sensitive, it’s driven by throttle position and RPM.
 
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I don’t have any solutions. Just wanted to say that I’m another with the same problem as Piggy. Been there since I bought the bike in 2007. I’ve been out of any serious riding for a couple of years and forgot how annoying it was until I went to Deal’s Gap last weak. You just can not get back on the throttle in a corner in 2nd or 3rd without a jerk that scares the crap out of me when I’m almost scraping foot pegs. I have spent hours concentrating on my throttle control over the years thinking it was just me because I am certainly no expert rider, mechanic or diagnostician. The only solution I have found is riding the rear brake until I’m past the lurch. But, I am now convinced it is the bike and wound up here after googling to find a fix. I love my 6 and have some mods/work I want to do on it but this throttle thing is a first and a must. If I can’t get it fixed I will sadly have to part with it and go to an mt-07 or mt-09. I really appreciate you guys and all your info and am intently following. Thanks!
 

Gary in NJ

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So I’ve been giving some thought to the throttle response issues that some experience. From what I gather, the real complaint is a delayed response off idle. I don’t hear that the problem exists from part-throttle roll-ons. Further, the issue doesn’t necessarily present itself while the bike is in neutral. This suggests that the ECU is using either speed related data or gear position to change from a “neutral” map to an “in-motion” map.

There are two parts of the EFI system; The Fuel Delivery System and the Control System. Hear are the parts that make up each:

Fuel Delivery System
  • Fuel pump
  • Pressure regulator
  • Fuel injector
  • Throttle body
Control System
  • Engine Control Unit
  • Throttle position sensor
  • Intake air pressure sensor
  • Coolant temperature sensor
  • Crankshaft position sensor
  • Intake air temperature sensor

Does anyone notice what is missing from these lists? Speed or gear-position data.


For those of you that have this problem, can you conduct some tests for me?

Test 1. Confirm/Disprove that the delayed throttle exists in neutral.

Test 2. While in motion and the problem is present, determine if the delay is a result of throttle position, or time.

Test 3. Confirm/Disprove that the delayed throttle exists only from an idle position, not a part throttle roll-on.

Test 4. Confirm/Disprove with the bike in motion, but in neutral, that the delayed throttle exists

Test 5. Confirm/Disprove with the bike in motion, in gear but with the clutch engaged, that the delayed throttle exists

Test 6. Confirm/Disprove that the throttle delay issue is NOT present in 6th gear. (added from post #71).


Depending on your inputs we can determine what ADDITIONAL input the ECU reads besides the noted Control System inputs. This problem could be as simple as a speed sensor or a faulty neutral/gear position switch. If one of the above sensors has a fault, it registers a fault code, however if other data is being used no fault codes exist for the failure.
 
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Morelius

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Ecu knows the bike is in motion by the speed sensor. Check diagnose code 07. Mine has no errors in the error log (diagnose code 61).

It's difficult to test the delay only by ear. I mean in neutral or clutch engaged. In fact i think there is no delay in these situations but i will double check anyway.

Coming back to my previous idea. I will try anyway to install a O2 eliminator and load a map again because i had random good throttle response last time i've gone out to ride and mess with the pc3

From dynojet:

Dynojet O2 Sensor Eliminator​

On bikes that use an O2 sensor in the stock exhaust have a closed loop area that can not be adjusted by the Power Commander alone. If you make adjustments with the PCIII in the closed loop area the O2 sensor will sense these changes and the ECM will alter the fuel curve accordingly. If you want to have full fuel control over the entire RPM range of your bike then you will need to bypass the closed loop area which the O2 eliminators will accomplish. If you are looking for the best fuel economy and not worried about making changed to the closed loop area you can leave the stock O2 sensors connected and still make changes outside of the closed loop area with the PCIII.

 

Gary in NJ

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The goal should be to address the root cause, not to create a work around. Regarding the speed sensor:

Fault Code 42 = Speed sensor, neutral switch
- No normal signals are received from the speed sensor; or, an open or short circuit is detected in the neutral switch.
- Fixes the gear to the top gear.
- Malfunction in the engine side of the neutral switch or malfunction in ECU.
- Bike is rideable
- Diagnostic Code 07 (speed sensor) or 21 (neutral switch)

Checking the Speed Sensor
- Place voltage tester on the White and Black/Blue wires, when sensor is ON 4.8VDC, when sensor is OFF 0.6VDC

If the speed sensor is at fault, and when it fails it fixes the fuel map in that for 6th gear, then this throttle delay should not be present in top gear. I'm wondering id there is a threshold case where the speed sensor has failed, but isn't being reported out.

Test 6. Confirm/Disprove that the throttle delay issue is NOT present in 6th gear.
 

Macconraoi

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Its a common thing with the FZ6, and the harder you work on smooth roll on throttle with fast track riding at high rpm, the more obvious it becomes.
Some say they don't experience it but I believe its almost 100% of all FZ6s.

I am glad to find so much info on it on this forum, as after posting on a UK Facebook group, some told me it was my riding. I worked tirelessly to improve my inputs... but finally took to recoridng my throttle movement v bike response and it was so obvious it had this dead spot. Which when you're really on it on track, higher rpm, crack the throttle mid turn, its violent sometimes and instructors have a go at me for being too brutal with the throttle!

Anyway, my bike is a 2008 FZ6s. I love the thing. But if I cant solve the throttle issue, or seriously improve it, I have to look for a different bike, I've ridden other modern FI bikes and they are smooth.

What I have done so far;
Checked and adjusted throttle cable, perfect.
Checked the TPS via onboard diagnostic mode, goes from 0% to 1% perfectly, as soon as the throttle moves. No jumping.
Balanced the throttle bodies.
Fitted free flowing exhaust and decat.
Adjusted C02 levels via on board diagnostic mode.
Ignition advance cog/wheel.
(bike is fully serviced and up to date, always use 97/99 fuel, valve clearances spot on)

None of the above have made any difference to the throttle snatchy/jerk from 0% to 10% as you roll on. Very very very very notcieable in 2nd and 3rd at mid/high rpm. Less so at the same speed but in 5th or 6th. . . naturally.

I have heard Power Commanders can help.. but its more money I could put towards a different bike, which I don't want to do, but I have to spend wisely at this stage. (especially as the other weakness, the front end suspension, would warrant some money)

HELP!
Piggy

EDIT;

Here is a video of the issue, hopefully you can see it clearly enough.


I recorded this after adjusting the TPS to register 18-103, as advised on the thread below (no change)
What you're experiencing is the dreaded Yamaha fuel cut. Roll off the throttle above 5k rpm and the fuel is cut to the injectors. Roll on the throttle again and there's nothing for a second then you have power. It's a horrible thing for sure and only a remap of the ECU will cure it. TPS adjustment or a power commander still won't solve it. As far as I know its there for emissions control
 

Gary in NJ

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I'm trying my best to spot patterns. Here is one:

goose111 2009
Tony@west oz 2009
Piggy 2008
Morelius 2007+ (has O2 Sensor)
AJ Babaganoosh 2007
francesco21 2007
MattR302 2007
Tunker 2006
Macconraoi Unknown
Cumnz4U Unknown

All of these members have mentioned that their bikes have the fuel delivery issue in the last year (in this thread and others). It appears not to happen to bikes in the first few years of production.
 
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skelly

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I'm trying my best to spot patterns. Here is one:

Piggy 2008
francesco21 2007
Tony@west oz 2009
Cumnz4U Unknown
MattR302 2007
Morelius 2008+ (has O2 Sensor)
AJ Babaganoosh 2007
Macconraoi Unknown
Tunker 2006

All of these members have mentioned that their bikes have the fuel delivery issue in the last year (in this thread and others). It appears not to happen to bikes in the first few years of production.
You could be onto something, I have a low mileage 2004 FZ6 and it's silky smooth, clutch a little heavy compared to modern bikes but a superb bike in so many ways.
 

goose111

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I can confirm my 2009 has the same problem. You roll on 0-1% throttle so delicately and still the bike lurches forward upsetting the suspension . from there 1-100% throttle is smooth as butter!
 

Morelius

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300km of twisties today. Here is my report:

Test 1. Confirm/Disprove that the delayed throttle exists in neutral.

Throttle slack

Throttle delay

It's dificult to see it, maybe half to 1 sec. of delay but it seems there it is. Not sure. I would not put my hand on fire swearing it's present in neutral. Much easier to feel it rather than see it.

Test 2. While in motion and the problem is present, determine if the delay is a result of throttle position, or time.

I would say both. You can avoid it somehow if you turn the first milimeter of throttle very slowly. This is something impossible to do in most turns because your time is limited by the speed you're cornering.

Test 3. Confirm/Disprove that the delayed throttle exists only from an idle position, not a part throttle roll-on.

Confirmed. Once the first travel of throttle is done the rest is smoth as butter. E.g. 0-30% or 0-5% or 0-whatever TP = Snatch; 5-30 or 10-50 or 60-100 and so on = no problem.

Test 4. Confirm/Disprove with the bike in motion, but in neutral, that the delayed throttle exists

Impossible to test with certainty. Noise and no response feeling without gear engaged.

Test 5. Confirm/Disprove with the bike in motion, in gear but with the clutch engaged, that the delayed throttle exists

Impossible to test with certainty. Noise and no response feeling without gear engaged.

Test 6. Confirm/Disprove that the throttle delay issue is NOT present in 6th gear. (added from post #71).

Not present but i think thats because final gear ratio make up the problem. The snatch response it's very noticeable in 2nd and 3rd gear, little bit less in 4th, little bit less in 5th and so on until 6th. Obviously doing sharp turns in 6th gear it's not a solution. Anyway speed sensor is ok because you can check it in diagnose mode and it works, and works in neutral so it's not a transmision or sensor problem
 
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TownsendsFJR1300

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It looks like and sounds like just excess play in the throttle cable.

Did you try taking a little more out of it??

Excess play, as you noted would be more obvious (in the throttle /engine RPMs in the lower gears..

Also, keeping the idle set at the 1,300 RPMs should help. Lower idle RPMs would exacerbate the issue..


.
 

Morelius

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It looks like and sounds like just excess play in the throttle cable.

Did you try taking a little more out of it??

Excess play, as you noted would be more obvious (in the throttle /engine RPMs in the lower gears..

Also, keeping the idle set at the 1,300 RPMs should help. Lower idle RPMs would exacerbate the issue..


.
No. It have less play than specified in the service manual (1-2mm vs 3-4mm). I tried more play and 0 play. This is not the problem.

The same with idle. Now its near 1400-1500. When it was 1100-1200 the issue was worse, that's true. Anyway, increasing idle make up the problem too but it's still there.
 
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