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04 yz450 throttle position sensor unplug it or not

By dwnlowx,
in YZ400F/426F/450F/450FX

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dwnlowx

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evey body should be doing this mod it really helps alot you will feel the difference just ride how your bike is now and then unplug the sensor after you ride it for a while with it pluged in and you will see the difference

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mxracer206

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:worthy: it really helps , ride your bike with it pluged in then after half of the day unplug it and you will notice the difference for sure that way

Then ride it on a dry slick track and check lap times, I bet they are faster with it plugged in. I doubt the factory invested money in this technology without a lot of testing. It makes the bike more tractable and easier to ride for a whole moto.

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NM_KDX200

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I'd already read that.

What the manual was referring to was removing the sensor where it attaches to the carb body. So, I didn't do that. I just unplugged the wires where they're zip-tied to the frame.

I didn't like it. It smoothed out the powerband, but it seemed to do so by taking away the initial low-end hit. I took the Q2 silencer off, put the stock one back on, rode the bike around my turning-practice track (flat, but lots of different turns) and was happy again that the low-end kick was back. Then I disconnected the TPS and rode again. It was definitely smoother down low but felt very much like the Q2- flat and dull, like my TTR-125 instead of a YZ450F. Mid-range was fine but in my informal roll-on wheelie-test, with TPS, the bike immediately starts lifting the front wheel until about 1/3 throttle, settles it back down a little, and then really lifts it past 1/2 throttle. With the TPS disconnected, it didn't wheelie at all until 1/2 throttle or so and by then, my ground speed was too much. No TPS feels like an XR250. Bleah. I re-connected the TPS and the power was immediately back again.

This makes a really big difference in, say, my whoop section. With TPS connected, I can come out of the corner low in 3rd and immediately lift the front wheel over the first 4 whoops in my 8 whoop section. I let the rear settle into the next one, give it a little gas, and POP!, I'm out of the whole section in basically 2 consecutive wheelies. With TPS dis-connected, I can't do that and it's much harder to get the speed and power immediately after the corner.

So, I'm back to stock again- stock silencer, TPS connected. It's good to know what the TPS does, though. On a really slick course, I might disconnect it, but if there's any kind of traction, I'm leaving it alone.

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grayracer513

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I've never been entirely certain why the guys who wrote the manuals have their knickers in such a knot over removing the TPS. It can be re-installed and adjusted to a precise point using a volt meter, as the manual shows. Removing it would leave an open hole in the carb body, though.

Mine is connected. The effect that disconnecting it has on each different year model will vary, too depending on how each engine reacts to being converted to a 2D ignition map. Your description of how your '04 runs with it unhooked does not really surprise me.

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