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Author [NL] [FR] [ES] [DE] [SE] [IT] [NO] [MY] Topic: DIY snatchy Throttle cure?  (Read 13967 times)

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Offline Danno

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Re: DIY snatchy Throttle cure?
Reply #20 on: February 15, 2020, 03:53:22 PM
Sent my ECU to Ivan last Monday....from UPS store in northeast Indiana, at 6PM, to his South Carolina location. He called me to say it had been programmed and on its way back on Wednesday.  I had it back and in the Z before 2PM on Friday.  That timing certainly surpassed my expectations. Firing up the Z bought a more reasonable fast idle and smooth warm up.  If ride ability, once the snow/ice/cold is gone, is as good as the time service, I will remain one happy camper. 
2018 Z900RS

Offline friedel

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Re: DIY snatchy Throttle cure?
Reply #21 on: April 07, 2020, 02:55:33 PM
Hello there,
(and thanks in advance to Notsoaverageguy, author of the opening contribution)
I have measured the factory setting of my throttle potentiometer with a multimeter. The value between the middle pin (2 in the picture) and the "front" pin (3 in the picture) is 1.99 kOhm for me.
After loosening the screw at the potentiometer by about 1/2 turn the potentiometer can be turned. (Tool: TT25, soldered with open-end wrench, picture in the appendix, so you don't have to remove anything from the bike). Gently move the potentiometer clockwise by about 1 degree. I have set the value to 2.05 kOhm.
You will love your motorcycle more than before.
Greetings Frank

Offline silverjoe

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Re: DIY snatchy Throttle cure?
Reply #22 on: April 07, 2020, 07:51:07 PM
Good to hear Danno I think you will be very happy.

Offline hell-wart

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Re: DIY snatchy Throttle cure?
Reply #23 on: April 07, 2020, 09:38:02 PM
*Originally Posted by friedel [+]
Hello there,
(and thanks in advance to Notsoaverageguy, author of the opening contribution)
I have measured the factory setting of my throttle potentiometer with a multimeter. The value between the middle pin (2 in the picture) and the "front" pin (3 in the picture) is 1.99 kOhm for me.
After loosening the screw at the potentiometer by about 1/2 turn the potentiometer can be turned. (Tool: TT25, soldered with open-end wrench, picture in the appendix, so you don't have to remove anything from the bike). Gently move the potentiometer clockwise by about 1 degree. I have set the value to 2.05 kOhm.
You will love your motorcycle more than before.
Greetings Frank

Hi Frank,
can you send a picture with the location of the sensor
Greets Holger
My bike history:  Yamaha TY50, Suzuki GT250, Honda CB 650, Kawasaki Z 650, Kawasaki Zephyr 550 + Yamaha XS 400, Harley Sportster 1986 + Kawasaki Zephyr 750 D,
Today: Kawasaki Z900 RS + Harley Sportster 1986

Online Pappy

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Re: DIY snatchy Throttle cure?
Reply #24 on: April 08, 2020, 03:15:08 AM
I remember changing the TPS voltage reading on a 2004 Beemer I had and it did make a noticeable difference on that engine. The engine is shutting off on decel and back on again after a shift into the next gear or whenever the throttle is blipped or run as Ivan shows in his vids. I will check my settings on this bike .....

Offline friedel

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Re: DIY snatchy Throttle cure?
Reply #25 on: April 09, 2020, 08:20:28 AM
location of the sensor:

Offline hell-wart

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Re: DIY snatchy Throttle cure?
Reply #26 on: April 11, 2020, 08:48:37 PM
I have done the TPS sensor measurement today.

According to Friedel, I should change the setting to 2.05 kOhm

My bike is running fine with the ECU flash and a DNA airfilter
but I will make a tool and give it a try.


Maybe some of you can provide their data to get an idea of the range

see my value below.

My bike history:  Yamaha TY50, Suzuki GT250, Honda CB 650, Kawasaki Z 650, Kawasaki Zephyr 550 + Yamaha XS 400, Harley Sportster 1986 + Kawasaki Zephyr 750 D,
Today: Kawasaki Z900 RS + Harley Sportster 1986

Offline awaK

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Re: DIY snatchy Throttle cure?
Reply #27 on: August 17, 2020, 07:31:00 PM
First I want to thank Notsoaverageguy for the starting inputs and Friedel who took the risk to fiddle with the TPS settings and described how he did it. Encouraged by Friedels result, I followed what he did (the TPS sensor factory value and new set for my bike are found below) and I have to say that I am also very happy with the results on my RS  :169:. The throttle response has smoothed to what probably is best possible without a ECU reflash. The reason in my understanding is that the TPS sensor is now better calibrated with the actual throttle butterfly position. Of course the fuel cut-off is not eliminated and therfore the time delay for the injectors to restart remains. If the throttle (from closed throttle/ fuell cut-off) is fast-reopened, then due to the delay the bike still feels a little snatchy (if the reopening of the throttle is really fast, then the bike feels very snatchy), but if the throttle is gently/slowly reopened then the transition is now absolutely smooth.

Here is how I proceeded and how I set the TPS to its new setting. I followed the guidance of Friedel and made the same tool with a TT25 bit and a wrench for loosening the TPS fixation screw. I also used Kawasaki special cable"Throttle Sensor Setting Adapter: 57001-1538" to readout the value of my TPS and then set it to its new value. I recommend highly this relatively cheep adapter, it makes things easy. I also followed the recommendation of the workshop manual for the TPS setting value.
The whole procedure (loosing the TPS fixation screw, moving slightly the TPS sensor -definitively only about 1į if not less) and re-tightening the TPS fixation screw is definitively noting for the faint hearted or for any with the gross motor skills. The room for the tool is quite limited and the slightest movement of the TPS sensor affects its value. Re-tightening the TPS sensor also slightly changed its value, so that I needed a few try and error until I got the desired value set.

Now to my procedure and values (and sorry for the amount of numbers): The manual states the the TPS Output Voltage (between Pin 2-3) has to be in the range 1.02 - 1.04 Volt at nominal Input Voltage (Pin 1-2) of 5.0 Volt. If your nominal Input Voltage is not 5.0 Volt, then the Output Voltage range has to be corrected in direct relation. My Input Voltage (Pin 1-2) is 5.02 Volt and my (factory) Output Voltage (Pin 2-3) is 1.025 Volt. Now my Input Voltage is so close to 5.0 Volt that in my case I would almost not need to corrects the value in relation, but if somebody wants to follow what I did, he may have to correct his value if his Input Voltage differs, so I present the exact calculations:
The TPS Output range corrected for my slightly higher Input Voltage of 5.02 Volt is: 1.0241 - 1.0442 Volt (higher by factor of 5.02/5.0). The measured (factory setting) Output Voltage of 1.025 Volt for my TPS is in the admissible range, close to the lower admissible value. I want now to set it to the highest admissible value (probably what Friedel did). In my case this would be 1.0442 Volt, or a factor 1.0442/1.025 = 1.0187 higher than actual. If instead of Voltage measurement one uses the resistance reading of the TPS between (Pin 2-3) then in my case it amounts to:
Direct measure of the resistance of the TPS sensor (Pin 2-3) is 1.899 kOhm. New target setting = 1.899*1.0187 = 1.934 kOhm. I managed (with a little luck) to set my TPS to 1.93 kOhm, close enough for me :-).
It can be remarked that the value (resistance value  Pin 2-3) I measured and the value I set the TPS differ both from the ones of Friedel. I strongly recommend not to simply set the TPS to 1.93 kOhm (my case) or to 2.05 kOhm (Friedel) but in relation to the actual factory setting value as described above.

... now I  don't recommend to anybody to follow the procedure. Kawa doesn't want us to do that and you risk to break your bike ... Personally I am very satisfied with the result. :152:

Offline Ride70

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Re: DIY snatchy Throttle cure?
Reply #28 on: October 11, 2020, 01:51:40 AM
I had Ivan do a stock ECU reflash for my Cafe. Received and installed it this past Wednesday. Rode 100 miles today on my regular roads. Totally different bike. Smooth, fast, eager, no flat spots or surging. The control I now have through low speed corners is phenomenal. Shifting is butter smooth. Still has a slight click in and out of 6th, no problem. Downshifting and deceleration are so smooth I barely need the brakes. Engine runs cooler. Not sure if it is my imagination but think it has more of a growl. Mpg down slightly from 49 to 47.5. An absolutely tiny price to pay for the way it now runs. Iím finally enjoying the bike rather than fighting it. No regrets!

Offline RobísZ

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Re: DIY snatchy Throttle cure?
Reply #29 on: October 23, 2020, 02:53:18 AM
I also had my ecu flashed by Ivan, first start was a check engine light, hitch turned out to be the O2 sensor.  Shut that light off with OBD2. But I do still have the snatchy throttle issue. I havenít really been out on. The bike since a back injury. I went to ride today and had the same problem rolling into a turn from stop or low speed.