Diconnected TPS...good results WR450


28 replies to this topic
  • TheGuy77

Posted March 11, 2007 - 10:37 AM

#1

Just got back from a quick ride around my neighborhood. My 2003 WR was surging while traveling at consistant speed (55-60mph). With the TPS disconnected, the surging was almost non existant. Before disconnecting, I was unable to ride at a steady pace without the bike cutting out. Power was excellent as long as I was steadily adding more throttle.

I do wonder if having the TPS disconnected, the ECM may get incorrect info and not adjust the timeing correctly? Any thoughts? Long term effects?

I also am wondering if I should adjust the TPS and possibly get the same results.


:applause:

  • Audun

Posted March 11, 2007 - 10:50 AM

#2

forumsearch?

  • yamageezer

Posted March 11, 2007 - 07:15 PM

#3

Just got back from a quick ride around my neighborhood. My 2003 WR was surging while traveling at consistant speed (55-60mph). With the TPS disconnected, the surging was almost non existant. Before disconnecting, I was unable to ride at a steady pace without the bike cutting out. Power was excellent as long as I was steadily adding more throttle.

I do wonder if having the TPS disconnected, the ECM may get incorrect info and not adjust the timeing correctly? Any thoughts? Long term effects?

I also am wondering if I should adjust the TPS and possibly get the same results.


:applause:


Dude, just adjust your TPS. My bike use to do the same thing as yours but since I calibrated my TPS, all is good...

  • Ditchdigger

Posted March 12, 2007 - 06:08 AM

#4

I had exactly the same problem on my 04. I checked it after searching and reading much of the info. on here. It was set however within the tolerance allowed although it was at the lower end. I think the allowance was anything between 0.58v and 0.78v. Mine if I remember was set at 0.61v. I adjusted this up to the top end and had a reading of 0.76v. Problem solved. The stutter has gone at constant throttle. Result!

This is easily done just loosen the TPS slightly and with your volt-meter test the yellow and black wires whilst the bike is idling. This I did by inserting the probes into the connector block just above the TPS. Only very fine adjustment is required. This thing is very sensitive.

Wouldn't have known about this but for the info. on here. Good Luck.

  • TheGuy77

Posted March 12, 2007 - 09:07 AM

#5

Thanks for the info. Much appreciated.:applause:

  • byggd

Posted March 12, 2007 - 12:31 PM

#6

Disconnected is the way to go on the street but most have found it better connected off-road.

  • wingnut16

Posted April 18, 2007 - 08:30 PM

#7

After researching this problem (because I have the same one) and finding this post, I adjust my TPS this evening. I set it at 0.76 volts as mentioned earlier in the post. But I still have a slight shutter at consistant throttle. Has anyone set the TPS voltage just a little above the spec window, say 0.79 to 0.81 volts? And fixed the problem? or does it start to get worse again? I will most likely try this tomorrow night and report back, but if someone has done it, it might save me some time.

Thanks,
wingnut16

  • Thumper_Bloke

Posted April 18, 2007 - 09:07 PM

#8

I adjusted mine to .80volts, but the studder is still there. I am willing to try higher, but i think soon i'm going to go with an aftermarket ignition box.

There is no harm in leaving it disconnected, all bikes at one time did not use a TPS. Some didn't even use advance.

  • BigIan

Posted April 19, 2007 - 12:11 AM

#9

Just out of curiosity, how exactly do you adjust the voltage? I am experiencing a similar problem and have yet to get my grubby paws on a voltmeter, but I cannot foresee how to actually manipulate the voltage, and none of the posts i have read say how.:thumbsup:

  • ARin

Posted April 19, 2007 - 12:28 AM

#10

i think its like a potentiometer. i think you turn the plug, and then tighten it back down when you get the voltage you want.

i think the manual explains it in pretty good detail.

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  • BigIan

Posted April 19, 2007 - 12:32 AM

#11

Thanks! After reading your carb post, I'll believe anything you say (almost)!:thumbsup:

  • Ditchdigger

Posted April 19, 2007 - 01:13 AM

#12

Just out of curiosity, how exactly do you adjust the voltage? I am experiencing a similar problem and have yet to get my grubby paws on a voltmeter, but I cannot foresee how to actually manipulate the voltage, and none of the posts i have read say how.:ride:


Dead easy, just slacken the two screws that hold the TPS in place. Not too much mind as once you turn the TPS either clockwise or anti clockwise to start to change the voltage readings. Then the manual states that you back probe the two wires (Yellow & Black) which leave the TPS & go into the connector block just above.

Ideally another pair of hands is needed at this point as you need to move the TPS in one direction or other to get your settings whilst trying to keep those probes from your voltmeter inserted, not to mention trying to read the display on the voltmeter which is probably dangling around facing the wrong way. Tricky, but not impossible. Again just don't loosen the TPS too much as it is way sensitive. Funny thing is, after adjusting mine a while back and testing the bike it ran fine. Having dusted it down over the weekend I went for a spin and my stutter is back. The only difference being that then it was rather cold, now the weather has picked up and we have gone from a few degrees to 22 on Saturday, I don't know if there is something else causing this problem? :worthy: :ride:

Have done all the free mods on the bike. E.g. Opened up air box / removed snorkel / bigger main jet – 170 (was 165) Bigger pilot 48 (was 45) 0 leak jet and the needle is on the 4th groove. Throttle stop also done. And am running an FMF Q pipe. No grey wire mod as this model doesn’t have one.

Going to have another look at the weekend and scratch my head some more. Would appreciate any feedback / advice also. :p :thumbsup:

  • GCannon

Posted April 19, 2007 - 08:29 AM

#13

How about we Adjust the TPS to the high end of the voltage scale. Per the service Manual as ARin suggested. Then we raise the needle one slot and see how that works.:thumbsup:

  • Ditchdigger

Posted April 27, 2007 - 06:35 AM

#14

How about we Adjust the TPS to the high end of the voltage scale. Per the service Manual as ARin suggested. Then we raise the needle one slot and see how that works.:applause:


GCannon,

Thanks for the advice. Haven't had a chance to look at this yet. Hopefully I will get time this weekend. Do you think I'm just running a little on the lean side? As I think I set the fuel screw to 1 & 3/4 turns out. Although the plug looked fine when I first rode it and checked. Since it has become warmer my stutter has come back. So will look at the plug again, although I know this will only really tell you if its running far too rich if its sooty or white if overly lean. I wonder if I should just try and richen it up a bit before I take the carb apart to move the needle one slot.

Again, any advice is much appreciated.

Oh, I adjusted the TPS previously to the top end - .76. Max setting is .78 according to the book.

Dominic

  • GCannon

Posted April 27, 2007 - 09:05 AM

#15

Do you think I'm just running a little on the lean side? As I think I set the fuel screw to 1 & 3/4 turns out. Although the plug looked fine when I first rode it and checked. Since it has become warmer my stutter has come back. So will look at the plug again, although I know this will only really tell you if its running far too rich if its sooty or white if overly lean. I wonder if I should just try and richen it up a bit before I take the carb apart to move the needle one slot.


Dominic


I think you may be a little lean at constant throttle small throttle opening. if you have your jetting close dont change too many things at once. raising my needle helped me richen the quarter throttle constant speed. I only noticed the stutter on the road never in the dirt. you have already riched your pilot circut so you are looking for fine focused adjustment. If you are happy with your current setup just move the needle up one slot and see if the stutter diminishes then you know you are making the right changes.:applause:

  • Ditchdigger

Posted April 29, 2007 - 11:58 PM

#16

Thanks very much for the advice. I will hopefully get chance to make these adjustments later in the week. Fingers crossed.

  • Strattos

Posted July 23, 2007 - 01:59 PM

#17

I'm having similar symptoms to some of you guys - engine actually breaks down about half throttle.

Confirmed its not jetting, as i've been up and down the lean/rich scale with no joy.

Local dealer said it could be the TPS. About to test today. If it is the TPS and I take the easy way out and just disconnect it, will I notice any impact on performance, and if so how?

  • MaxPower

Posted July 24, 2007 - 01:02 AM

#18

[COLOR="Green"]correct jetting fixed my stutter. I plugged the TPS back in[/COLOR]

  • Strattos

Posted July 24, 2007 - 12:46 PM

#19

All my problems fixed by disconnecting the TPS. Should have done it months ago.

Just did a search for TPS in the jetting forum and judging by the number of posts it's a major source of jetting dramas.

  • ARin

Posted July 26, 2007 - 12:46 AM

#20

All my problems fixed by disconnecting the TPS. Should have done it months ago.

Just did a search for TPS in the jetting forum and judging by the number of posts it's a major source of jetting dramas.


a bike CAN be correctly jetted with the presence of the TPS.....however it leaves little room for error.




 
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