Well, I checked the TPS on my 2010 TE250 and it was 102.4 and 925mv. I adjusted it to 100.8 @ 1030mv which cleared up the off idle stumble. However, this raised the idle to like 2800rpm with 3 turns on the air bypass screw. I then raised it to 101.2 AT 1016mv...the stumble did not return and the idle stabilized at about 2100rpm. I run a TC250 mx pipe which is still quiet that required me to richen CO1 to 107 from 103. my Co now is 107.5 105 104. So my question is what is the recommended TPS for the x-light bikes? I see the 2009's were 100.5 and I red that the 2010 250 was running a little better at higher numbers....what are others running? Thanks Rich
Ive fiddled with mine to both ends of the spectrum and am settled at 101.5. My bike simply dosen't run well at the 100.4-8 reguardless of CO1. My bike is a 11 TE 250.
Well, at 101.2 i noticed the idel would hang for a bit before dropping so I adjusted my tps to 1011mv @ 101.4 and the stumble appeared to creep back in. I'm going to drop it back to 101.2 @ 1016mv and leave it. I guess the hanging idle shoud keep it from stalling with the rear brake. i also tried my COs at 110 109 108 and their was more snap and power but the motor did develope a major bog at mid openings. 108 108 108 seems to have the beter power than lower but it seems to run a little cleaner @ 107 108 105.
Any idea how i can go about adjusting the % throttle scale W/O an ibeat? I have seen instruction on TPS reading with a voltmeter, so thats going to be easy to work with. Just not sure how I can get rid of the flat,almost unresponsive bottom end that I need for the technical stuff. This is for a 2010 250 txc... Oh i have a JD computer, but no Ibeat. Bike is great... I am riding faster but the bike makes you,.... I suppose.
Basically the ECU has a stored voltage as a 'zero point' being "closed throttle" (this number can be changed only with Ibeat) The TPS will put out a voltage and either be AT, ABOVE, Or Below said Zero Point at Closed throttle. (this can be changed by adjusting the throttle stop) If your bike is set up corectly with IBEAT or you assume it is close- you can take a voltage reading with a volt meter and continue to test for and adjust to that closed throttle voltage. You would have to change the Hard Stop to adjust it. This would be equivalent to clicking "set" on Ibeat without having adjusted for the correct WOT % for your model 100.2 for 450/510 100.2 for 250/310. SO you can "kinda" have it correct but not 100% correct by simply using a voltmeter. Your WOT % will therefore not be in that WOT spec range- with good or bad results. Some have great luck with the WOT TPS specs of 100.2/100.4 but apparently some with 2008s and xlites have not. Bikes I have tuned seem much better off at the 100.2 spec but I have only done 2009 and 2010's that were either 450s or 510s.
Anyone else spent some time playing with a 2010+ TE250 and have a TPS setting that they have settled on? So far: R_Little 101.2 JasonfromMN 101.5
The xlites are a different beast- I accept that- but these higher TPS WOT %'s that are being used on them result in the butterfly being open further meaning more air at idle and small throttle openings. If it is common for xlites to need more air at small throttle openings wouldn't it then be expected that CO1 should be leaned rather than opening the butterfly (throttle stop)? Once upon a time- it was suggested that 100.2% should be used for 450/510s that number has shown to be accurate. At that same time 100.4 % was suggested for 250/310s- initially those numbers were not reported as problematic- BUT maybe that's because those 250/310s were not xlites. Still its the same mikuni system- one might wonder why any difference in WOT% would be needed at all. A baseline should be found and established. For the 450/510 I am confident that it has been found at 100.2%. Guess the verdict is still out for the 250/310s. We are seeing guys report higher numbers of 101.2-101.5 for the 250/310s and I just wonder why the butterfly needs to be open further for xlites (100.2-101.5). Is it because of the CO settings, air bypass adjustment, is there a section in the CO1 setting that is overly rich compared to the rest of the map in that section- and changing the WOT that high corrects it? seems there's still be a residual effect... Did you guys ever try 100.4 and then adjust the air bypass and try different co1 settings? I guess I am just inquisitive and trying to push this topic along with some speculation- carry on
On a few of the '11 and '12 Xlites I have kept the O2 sensor plugged in and performed a feedback reading adjustment. Every single Xlite has needed anywhere from a 99%-97% CO1 adjustment to get feedback at idle to the 100% realm. However when fiddling with a few powered up '11 TE250's with or without the upgraded injector and fully powered up, I did not get any better performance by reducing the CO1 (less then 100%) I have found most respond well to a CO1 adjustment with only very little adjustment if any to the CO2/3 values, but they are all different, even when two exact models/year bikes are prepped at the exact same time so no temp or tech variables. It's really a matter of taking the extra time to fiddle with the given settings to get it in the happy spot for each individual bike and it will most likely change from brand new to broken in after 10-20hours depending on how it's ridden which will necessitate more fiddling with an Ibeat. Then add a power commander or JD tuner.
In my head, the TPS WOT% numbers work the opposite way. The higher the TPS value at WOT, the less the throttle stop has been screwed in and thus the throttle plate is more closed at idle(i.e. smaller opening). Do I have it backwards?
I guess I had thought of it backwards if I refer to your numbers and your voltages are closed throttle (higher voltage= larger opening /=/ WOT percent decreases as closed throttle volts increase at set tps...?- I just over thought it- but I have to admit it confused me to think of- with all the steps involved and factors effected... something I hadn't thought about much- maybe we got it now. I Have a heaache now... sorry if I confused anyone more
Could this let a 2010 TXC 250 start fine/normally, and after the bike is almost warm, you barly pull the thorttle and it dies.. every single time! It will start fine, will not let the throttle be pulled back. Valves have been checked, new pump, new starter, new wiring harness. This started after the last lap at Lorettas after water went over the tank. We had shrink wrapped the harness before this happened, and the bike has been dried out. This has been going on for over a month, and still no fix. NO one knows what is wrong with it, and we are at a loss!! ??
Could this let a 2010 TXC 250 start fine/normally, and after the bike is almost warm, you barly pull the thorttle and it dies.. every single time! It will start fine, will not let the throttle be pulled back. Valves have been checked, new pump, new starter, new wiring harness. This started after the last lap at Lorettas after water went over the tank. We had shrink wrapped the harness before this happened, and the bike has been dried out. This has been going on for over a month, and still no fix. NO one knows what is wrong with it, and we are at a loss!! ??
Good Stuff. I sold my TXC but I still like reading and learning about this. A little off topic but my take on this engine is people tend to think it needs more pull on the bottom but once in the RPM range it runs strong. I am not sure if it is just the design of the motor, Mikuni FI but I believe the air tract could be the cure for improved power instead of looking for the perfect TPS or CO numbers. Of course you need the bike to run good before messing with the air tract. I tend to think until the flow of air builds enough stream in the intake tract (air boot) is when this bike hauls the mail. I wish Moto Tassinari would design the air4orce intake boot for this bike. If you go too far rich with your CO1 the bike will be sluggish on quick throttle openings, it may run smooth but really the best way on all of this is with a exhaust analyzer like Seymore once rented. I hear the TC 250 air boot (non 2012) does make a improvement.
I think it is a valid question. The off idle stumble seems to go away with a lower 101.4 TPS because I guess it richens the idle mixture. I may set it back to 102.4 and see if it goes away with a richer CO1.....i believe it will. Right now I still have that hanging idle at 101.4 TPS.
Rich, I have noticed on my bike that I can cause a hanging idle by turning the bypass screw in too far. Have you tried turning yours out a little to get rid of the problem?
Can't say it's your problem but when I get my TPS out of spec it will cause a stumble with a twist of the throttle. It will change how well/ poor it starts too.
I have to go out 4 turns plus to get the idle down....seems a bit harder to start now too. Just got a new ring gear from Bob Wallace.........old one was not worn, but it seems to bind less when hot now...makes a bit more noise now also..i guess it is looser now. I need to pull out the worm gear and see if it has 2 washers like yours.
