DR350 Thread

Discussion in 'Thumpers' started by leonphelps, May 16, 2007.

  1. RuggedExposure

    RuggedExposure Now with more rugged

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    Alright, put the new plug in. Bike ran great for a few minutes with only slight sputtering.

    I decided to take a look at the air/fuel mixture screw to see if possibly it was moved or needed adjustment. I turned it one full turn counterclockwise and the bike began running worse. I then set it back to where it was originally then turned it in one full turn and that was the most it would go in. The bike's behavior was the same: sputtering and popping out of the tailpipe.

    I decided to check the new plug, it looked like it was on its way to getting fouled.

    I then pulled the carb off and saw that there was fuel in the intake manifold.

    The float valve is sealing fine. I can't even blow air into the tube with the float raised.

    I then bent the tab on the float just a little to lower the level of fuel in the bowl and put the bike back together.

    It is back to running like pure shit. I am ready to unload a full magazine into it and forget about this POS Suzuki.
  2. 2old2Bbold

    2old2Bbold was 2bold2getold

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    Try checking both idle jets again, air and fuel and their respective passages. Also maybe some one has a spare cdi you can try.
  3. Stretch67

    Stretch67 Mad Scientist

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    He has an internal fuel leak...


  4. RuggedExposure

    RuggedExposure Now with more rugged

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    For the life of me I cannot figure out where the fuel is coming from. The float valve is sealing 100%...

    I got so pissed with it I ended up giving it full throttle for a minute to see if the motor would blow and I could be done with this pile of junk. There was a black cloud of unburnt fuel coming out of the tail pipe.

    I just took the carb off again and smoke came out of the intake manifold.

    Everything in the carb is in place and tight.

    The float seems to be at the right level... is there any way fuel could be coming through the pumper jet and into the intake???
  5. Stretch67

    Stretch67 Mad Scientist

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    EDIT - Whups, missed it. You just said you have a pumper. I had an idea, but it doesn't apply to your carb. Sorry about that.

    Seriously though... it's something small, probably rubber, allowing fuel to leak through to where it ought not be...

    Needle & seat, seat o-ring, pilot screw o-ring, accelerator pump seals & check valve, choke (enrichment circuit) plunger and / or seals.

    Make sure your jets aren't loose. I've heard of jets loosening up, raising hell with the mixture.
  6. mouthfulloflake

    mouthfulloflake Not afraid

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    the pumper piston just squirts fuel from the bowl, I guess if the pumper parts were missing it possibly suck fuel through that circuit, i doubt the parts are missing though.

    I think its more likely you have an obstruction in your air filter, is that a possiblilty?
    Or your choke is vibrating closed, I had one do that, and it was the exact same symptoms.

    edit-just read back a couple of pages to trace your findings so far.

    have you done a compression check?






  7. RuggedExposure

    RuggedExposure Now with more rugged

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    All of the parts are there for the pumper assembly... I just thoroughly cleaned this carb a few months ago and it was running like a top.

    How would compression affect it running rich?

    What do you mean by choke vibrating closed? It has the same behavior with the choke open or closed.

    These problems started right after I put on the Acerbis tank... maybe the extra fuel is putting more pressure into the line and its leaking somewhere into the intake???

    I have the carb totally disassembled now sitting it a bath of citric acid. I'll let it soak over night and put it back together tomorrow to see what happens. I guess my next step is to order a new TM33...

    I don't understand how this bike can run like a raped ape for a few months then on one 2 hour ride fall on its face?
    I should have listened to myself and not bought another carbureted piece of shit. At this point this bike has become a project vehicle and cannot be trusted to be reliable enough to be a daily driver.

    Hopefully by the beginning of March I can go to AZ and pick up a new Husqvarna Terra 650 (with fuel injection :clap).
    If a new carb doesn't solve this issue, I may be posting a new video on Youtube of me emptying a few mags with the AR-15 into this shit box.
  8. MrPulldown

    MrPulldown Long timer

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  9. shearboy2004

    shearboy2004 KIWIINUSA

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    It almost has to have something to do with this , did you wash the new tank out ? I have heard of lots of bits of plastic being in those new tanks .
    Are you sure of your cable routing under the new tank ?
  10. Stretch67

    Stretch67 Mad Scientist

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    Choke cable?
  11. shearboy2004

    shearboy2004 KIWIINUSA

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    Stupid me :lol3 I have too many bikes .
  12. mouthfulloflake

    mouthfulloflake Not afraid

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    low compression wont make it run rich
    but low compresision will cause it to runlike shitwhen engine warms up
    and low compression would make for poor combustion making the plug appear as if it isfouled

    remove your air filter verify nothing is obstructing the air inlet
    then try it with the air filter out

    also the slide wears on these carbs and they run poorly
    mine is worn and it just idles erratically


  13. RuggedExposure

    RuggedExposure Now with more rugged

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    I did blow it out with shop air before i installed the petcocks.
    Since this will no longer be a commuter bike, i guess I'll sell the Acerbis tank and put the stock one back on.
    It is still pretty much new, (it still is on it's first tank of gas) I'll let it go for $200. Any takers?
  14. markk900

    markk900 Been here awhile

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    I understand the frustration, but I think its time to take a step back and look at your symptoms.

    A key piece of information is the statement that it runs the same choke in or out....that indicates either so much extra fuel it can't run worse or that the enrichment circuit is at fault.

    Another thing you said is it was running fantastic, then you changed the tank from stock and it ran like crap. This makes it highly unlikely (but I supposed possible) that there is a mechanical or electrical problem with the bike (ie low compression, CDI, etc). It would be an amazingly bad coincidence. I'd also discount the pressure from the tank theory...but you can check that by running with only 1 gal in the tank to see - 1 gal exerts the same pressure whether its in a 4 gal tank or a 2 gal one.

    So it is really clear you are running too rich, which makes the bike run like doo doo after it warms up. I'd look at the choke itself - I've had Del'Orto carbs on my street bike where the plunger for the choke wouldn't seat correctly and that made the bike run poorly. Not sure about the pumper, but the plunger and knob should unscrew as a unit. Perhaps you got some crap under the plunger. When you rebuilt the carb did you take this out?

    Perhaps you should dump a magazine worth into an effigy of your DR to get out the bad karma, then go try again.

    BTW: are you really sure injection is going to be so much more reliable?
  15. 2old2Bbold

    2old2Bbold was 2bold2getold

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    If you take the choke plunger out be aware on some carbs the little ball/spring detent can go flying. :cry
  16. MrPulldown

    MrPulldown Long timer

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    Did you check to see if your slide is worn out. With the carb off the bike. Which sounds like it is out most days. Place your fingers on each side of the slide. If you can push it back and forth with a click click click, then it is most likley worn. Might be luck and replace only the slide. But like most on here will tell you, ASK BENDER, your pumper is toast.

    Don't think the new tank has anything to do with it.
  17. 2old2Bbold

    2old2Bbold was 2bold2getold

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    Might check the tank cap vent. If it's not venting right it should starve, not flood, but I've seen a lean condition that causes popping/missing fill the intake/carb/air filter with oily messy crap. Just throwing out guesses. Really hard to do this stuff long distance.
  18. 2old2Bbold

    2old2Bbold was 2bold2getold

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    I used one of these on my dr350. http://helusa.com/store/index.php?cPath=77_112&osCsid=1ae0212c91c4220c1f1476fa95a662eb Works/fits good. On another bike, I took the old hose to a place that makes hoses ( http://www.stuarthose.com/ ) for about anything and they made a rubber one from scratch for about $35.
  19. RuggedExposure

    RuggedExposure Now with more rugged

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    Its possible, I'll check that. But the bike only has about 4k miles on it. Could the slide cause it to run stupid rich?

    I'll try running it without the cap to see.

    Someone else mentioned on here, and talking to Bullittman281 over the phone, I may have one of those tiny air passages (fuel filter side of the carb) clogged up. Tomorrow morning I'll run some torch tip cleaners through there to see if any sand or anything comes out.

    Friday I'll be going back to town to run errands and I'll pick up the old tank (its at my shop) and install that back on the bike.

    The Acerbis tank is getting sold though. $200 o.b.o.
  20. slartidbartfast

    slartidbartfast Love those blue pipes

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    I doubt it. A badly worn, undersized or broken needle (tip missing) could though, as could a needle that is not seating properly in the slide for some reason.

    Try to blast some carb cleaner through those passages (always wear safety glasses, DAMHIK). If you get some squirting out, you know the passage is clear.

    Enrichener not sealing closed might cause some or all of the symptoms you are seeing too. You can blow carb cleaner through that circuit and see what happens when you open and close the plunger.

    Final thought is that if the float assy were bent or otherwise distorted to one side, it could be touching the inside of the bowl and hanging open