Yz426f to sensor

4 replies to this topic
  • JezShandy

Posted May 25, 2015 - 06:14 AM


Been reading About taking the wire from the tp sensor off on a yz426f and yes it does make it run as sweet as a nut with no missing on acceleration that has been plaguing me.
My Question is why wont it start unless I connect it back up? Is there something I am doing wrong.
Many thanks if you can help me.

Edited by JezShandy, May 25, 2015 - 06:15 AM.

  • tiffdogg

Posted May 25, 2015 - 06:50 AM


Need to reconnect it to a ground

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  • JezShandy

Posted May 25, 2015 - 11:25 AM


Hi tiffdogg
Many thanks for your reply. Could you elaborate a bit for me as to which wires I need to ground. Sorry not great with wiring.
Many thanks for taking the time to help.

  • G-BRO

Posted May 25, 2015 - 05:51 PM


I never understood why any properly tuned carb would run better with the TPS unplugged. I feel like it's only a bandaid to mask an underlying issue. Non EPA compliant carbs wouldn't have performance limiting equipment installed

Edited by G-BRO, May 25, 2015 - 05:53 PM.

  • grayracer513

Posted May 26, 2015 - 06:43 AM


The problems occur when the TPS gets flaky.  It's purpose is to give the CDI information about the engine's load state so it can map timing according to load as well as RPM.  With it disconnected, the system assumes full throttle operation and maps to that by RPM, so there is no reduction in heavy throttle performance, but there can be a drop in fuel economy and overall "sharpness" of response at part throttle.


The bike should start and run in a near normal manner with the TPS disconnected.  If it can't, the CDI may be at fault.  Try to find one you can plug in to try.

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