Ignition Timing VS TPS position

In many of the posts about the off idle hesitation, James Dean has recomended turing the base idle up a bit. I have also seen posts saying turning the TPS a little helps cure the hesitation.

Is there a chance that turning the idle up changes the TPS voltage enough at the new idle to change the ignition timing? I can't think of anything else that the TPS would be needed for other than timing.

Is there a way to check ignition timing with a timing light? I don't have my Shop Manual with me or I would check.

By the way I would like to thank James and Clark for sharing all their experience with us.

Another questions on the TPS.

I am YZ timed but I never moved the TPS. Are we supposed to move it if we are YZ timed? If so, which way?

If I am not mistaken, it is to the right and only a tiny bit. Is that correct?

Information from the TPS is used to change the timing curve, I have heard about folks who did notice an improvement by adjusting this. This would seem to indicate that small changes in throttle position (and therefore TPS readings) DO change the ignition timing.

Personally I’ve never checked either. You need an ohm-meter for the TPS but for the timing I imagine any inductive pick-up timing light would work. At idle the timing notch in the cover should be inside the H mark on the flywheel. I can’t remember if you’re supposed to time the bike with the TPS unplugged or not but the manual states anywhere inside the H mark is in spec (the H is just before the TDC mark and is probably about 5 degrees wide)…

BTW you need what is called a “tamper proof” torx bit (but I forget what size) to remove/adjust the TPS (torx bit with a hollow center).

Has anybody tried adjusting their TPS?


I have try countless time adjusting the TPS and this is my conclusion take note this might not work for you. This is my way of adusting First of all you must adust the fuel screw to the bext responce then you start to mass around with the TPS adjusting it bit by bit turning it clockwise and test ride the bike when ever you make a slight adjusting to the TPS. If you tune correctly the bike will pull hard on the crack of the throttle only and it will not effect others area. This is just my experience on the WR timing sea level and stock jetting.

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