Where are your XT250's...let's see them.

Discussion in 'Thumpers' started by MEDIC-0372, Nov 4, 2008.

  1. goofyjumper

    goofyjumper Adventurer

    Joined:
    Apr 25, 2015
    Oddometer:
    53
    Location:
    Selkirk, NY
    [​IMG]

    Group ride today: XT250, DRZ400, KLR650, and two CRF250s.

    40 miles of fun.
  2. Ken Hooligan

    Ken Hooligan aka Hooligan LT

    Joined:
    Jan 5, 2016
    Oddometer:
    474
    Location:
    WNC
    Photos of a Ricochet skid plate on a California model with the canister removed. Went the easy route and capped the throttle body line with a vacuum cap where it meets the canister.

    IMAG2661.jpg IMAG2663.jpg
  3. Kirt

    Kirt Biker Dude

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    May 12, 2005
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    Location:
    Ideeho

    Looks like fun and green stuff in the background.

    It'll be a while here. About 3' of snow on the ground.
  4. IkeKant

    IkeKant Adventurer

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    50
    Location:
    Lyons, Colorado
    No fair Goofyjumper. It's been snowing along the Front Range of the Rockies for three days. We measured twenty inches of wet snow in the yard today. The XT250 sits idle in the garage pining for Spring.
  5. LDRcycles

    LDRcycles Been here awhile

    Joined:
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    205
    Location:
    Sunshine Coast, Australia
    Meanwhile in my bit of Oz it's 90 something degrees american with 70% humidity. Got caught in a storm a couple of days ago and completely drenched, even with water across the road in a few places (only shallow mind) the XT chugged along without any complaint.
  6. Unclviny

    Unclviny Been here awhile

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    Oct 31, 2015
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    273
    It's so muddy here (Houston Texas) that I can not get onto most of the trails so today I rode to the battleship Texas (1914 - 1948) and played on sand with the XT.

    Vince
  7. Ki-45DSLAYER

    Ki-45DSLAYER Adventurer

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    Thanks, I never thought a 250 dual sport could be so much fun.


    Sent from my iPhone using Tapatalk
  8. CloudSplitter

    CloudSplitter Putterer

    Joined:
    Apr 6, 2014
    Oddometer:
    1,421
    Location:
    Northern West Virginia
    Just got my oversize tubes (but standard weight, Michelins) for my new, oversize, tires. Here are their weights (in the box, to carry as spare):

    Front, 90/90-21: 19 oz
    Rear, 130/70-18: 23.6 oz

    Did anybody else weigh their spare front tube?
  9. gscojo

    gscojo GaryJ

    Joined:
    Mar 7, 2010
    Oddometer:
    90
    Location:
    Minnesota
    Thanks for the info. I did get a spare and will post the weight.
  10. NJ-Brett

    NJ-Brett Brett

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    Location:
    Southern New Jersey
    Ok, I am wondering about the FI system on the XT.
    Most systems are about the same, my TU250 had a cat and an oxy sensor, as does my SR400.
    The Suzuki system worked very well, it had oxy sensor, intake air temp, two throttle position sensors for the two throttles, one cable operated, one motor operated by the ecu (like a CV carb setup I suppose), engine temp sensor, intake pressure sensor, crank sensor.
    It was not set lean from the factory because it had a cat, air injection and was fuel injected.

    My SR400 has a cat, air injection, a temp sensor for the engine and intake air, a fuel pressure regulator vacuum port, throttle position sensor, oxy sensor, crank position sensor and an idle speed control (stepper) motor.
    It also has a speed sensor, although I do not know what it is used for.

    What does the XT have?
    Must have a crank sensor, throttle position sensor, engine temp sensor at a minimum and should have intake pressure and temp sensors.
    Does it have an idle speed control device or is that static?
    Any sort of fuel pressure regulator tied to the air intake?
    Single throttle cable operated with position sensor?
    I guess it has no cat and no oxy sensor, which seems odd.
    Anyone know what the wr250 has?
  11. aguim

    aguim Long timer

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    As you said , all Injection Systems are more or less similar, with the XT's on the "simple"
    side of it (no cat., no O2 sensor). Looks like it satisfies EPA norms that way (i'd be curious
    to know exactly how...).

    -The TPS, Intake Air Temp. and Intake Vacuum sensors are all integrated in ONE module
    bolted to the right of the throttle body.
    -On top-rear of it is bolted the Fast Idle Solenoid (actuated by the ECU, according to engine
    temp.) It controls an air bypass inside the TB. Hot idle speed can be manually adjusted with
    the big philips screw beside the cable pulley.
    -There is no secondary throttle butterfly (and no corresp. tps).
    -The Crank Pos. Sensor is the usual pulser-type (part of the stator assy.)
    -The Engine Temp. Sensor is screwed to the back of the cyl. head, adjacent to the int. rubber.
    -The Pressure Regulator is part of the Pump.

    The fun of it is the AutoDiagnostic system. It will instantly flash a problem's code number, and
    even provide detail analysis of that problem, once put in DIAG mode. I checked this by
    unplugging different devices, and it works great. The un-fun part is that neither the main
    sensor module, nor the idle solenoid are sold separately ($$$...Honda sells such items for
    about 80$...).
  12. NJ-Brett

    NJ-Brett Brett

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    Thanks very much for the info!
    And the 300 ohms in the engine temp sensor wire makes everything good if you open things up a bit?
    A 500 ohm pot might be interesting to try, make adjustments on the fly and see how the bike responds.
    I had a setup like that on my TU for a bit but noticed no change until it was so rich it ran really poorly.

    It almost seems like Yamaha put FI on the XT to make it run better, not to meet emissions.
    No choke, no super lean burn.
  13. aguim

    aguim Long timer

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    Brett,

    I hate noise, so I wont touch the muffler. With the spark arrester removed, it makes a much
    "healthier" sound, and should be enough to "open it up", but...not for me...

    Adding more than 500 ohms to the ETS made mine way too rich, too, so I went down to
    300, and is satisfied that it wont hurt the engine. In April, I'll see how it affects mileage,
    plug color in more detail. A better idea would be a Power Commander (but it would KILL
    my KISS pride...).

    And yes, the engine runs great, stock . I just wanted it to run a tiny bit richer, knowing
    they are all running hot and lean nowadays.

    I have the shop manual, here, with all the data on the FI. A very simple system to understand
    and test, once one has a basic grasp of its operation.

    I hear you'll buy yours later. Why not ask for a carbed 2012 ? They are still available here in
    Canada. I could have asked for one, but was too much in a hurry to ride the 2014 in stock!
    The carbed one you'd already know by heart, just like the 225...

    Thinking about it , I'd be just fine with the simpler carb version.
  14. Unclviny

    Unclviny Been here awhile

    Joined:
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    Oddometer:
    273
    I do not like noise either so my plan is to drill out the muffler like the Z1-mod but using a hole saw the same OD as the outlet and then packing the muffler with muffler packing. I think that will take out some of the "bark" but allow a little freeer breathing.

    Vince
  15. aguim

    aguim Long timer

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    I tried this on a 80ish bike of mine. Spent a whole summer trying to get it right, and reliable. At
    the end, I came back to stock. There was always something getting loose, blocked, fluffing out
    etc.. Modifying a stock muffler can become a more troublesome adv than presumed, if one
    wants both the cake, and the eat. But who knows...
  16. aguim

    aguim Long timer

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    Brett,

    Reading back, I see your TU has both a cat, and an O2 sensor. With such FI systems (called
    closed-loop), the O2 sensor will "correct" any enrichening attempt (ex:300 ohms resistor)
    to pre-determined values. So that mod would be useless, indeed. When the R value becomes
    way too high for the sensor to make the appropriate correction, the ECU loses control and
    the mixture gets suddenly very rich.
    Modding a closed-loop FI system is a very sophisticated proposition. In my opinion, it should
    never be attempted. But the XT can take it, and feel better.
  17. NJ-Brett

    NJ-Brett Brett

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    10,410
    Location:
    Southern New Jersey
    Not really true.
    The oxy sensor only has control at mid throttle, mid rpm's (where the epa tests it!).
    Idle, full throttle (where the TU spent most of its time) the oxy sensor was out of the loop.
    My SR400 is like that also, narrow band sensor, limited adjustment range, and only operational at mid throttle and rpm's.

    People tend to think bike systems are like car systems, in control all the time and they are not.
    It sure would be nice if they were, automatic adjustment from idle to full throttle red line with open exhaust and air intake, or stock, the ecu would just set the air fuel ratio correctly.
    The bike systems use maps and just use the oxy sensor (if equipped) for fine tuning over a narrow range.




  18. aguim

    aguim Long timer

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    I never said your bike's ECU could cope with any shit you'd throw at it. Can you read English?
    I never said your O2 sensor had a "wide operational range", either. Quite the contrary. Again,
    can you read English ?
    You sound like a guy just out of wikipedia, with not much real knowledge of the things
    you are talking about.

    I wont comment anymore.
  19. NJ-Brett

    NJ-Brett Brett

    Joined:
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    Oddometer:
    10,410
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    You seem to be wound up a bit tight for some reason.

    I was just pointing out that the resistor mod (changing the engine temp sensor readings) works even with a cat and oxy sensor, but at mid throttle and mid rpm the oxy sensor will adjust or try to adjust the mixture to what it wants to see.
    Not a problem at all because its at mid throttle and mid rpm's, not maximum power points, or at idle.

    I have been messing with fuel injection on bikes and cars since its been out.

    Here is what you said:

    With such FI systems (called
    closed-loop), the O2 sensor will "correct" any enrichening attempt (ex:300 ohms resistor)
    to pre-determined values. So that mod would be useless, indeed. When the R value becomes
    way too high for the sensor to make the appropriate correction, the ECU loses control and
    the mixture gets suddenly very rich.

    And I said its not true because its not, its only true at mid throttle and mid rpm's, otherwise a resistor mod DOES impact things just as much as on a system with no oxy sensor.
    You need to differentiate between narrow band part time systems and full time wide range systems.
    If you change the coolant temp sensor readings on a car, you would get no change once in closed loop.
    A bike is not often in closed loop, and any 250cc bike is rarely in closed loop, maybe at 40 to 50 mph cruise...

    No need to get upset about bike talk.
    I did not say you were stupid, or an ass, just that what you posted above was not correct.
    Many people think the oxy sensor is always in control and its not, and when it is in control, it does not have much adjustment range.
  20. gscojo

    gscojo GaryJ

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    Minnesota
    Finally got around to weighing my spare. It's 32 oz. No wonder I couldn't stuff it in the spare tool pouch spot!

    http://www.amazon.com/gp/product/B008DE44L6?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00