End of the line with my DRZ400

Discussion in 'Thumpers' started by SierraCB, Nov 1, 2013.

  1. SierraCB

    SierraCB wadahp

    Joined:
    Sep 19, 2013
    Oddometer:
    122
    Location:
    Reno/Tahoe, Nevada
    So i'm basically on my last leg at this point, I have put so much time and money in this things already that I can't keep up with other things. Friends have DRZ's that have 0 problems, this has them all it seems like.

    I'll start with specs.

    2000 DRZ400 Kicker:

    Powerbomb header with Ti 4 Muffler
    3x3 Mod
    Newly Installed MCCT
    FCR Slant Style Carb (non MX)

    Jetting:

    Main 148
    Pilot 45 (Brand New)
    Slow 65
    Stock Needle Position
    Fuel screw 2 turns out, (is it supposed to be completely bottomed when turned out? Seems like a lot of pressure)
    Stock Air Jets
    Removed Coast Enricher and plugged the block hole, connected the two carb holes with hose
    Removed Hot Start and plugged everything accordingly

    Firstly this bike would NOT idle without the choke, cleaned and bought a new pilot jet, still wouldn't. Took it to a shop, they cleaned it more thoroughly I asssume. Got it back and seemed to run OK. Would hesitate over 1/4 if ripping on it. Took it to the dirt and the idle issue came back. Would idle for around 15 seconds then stumble and die.

    Took the carb off to check everything, put a 148 main in to maybe solve bogging. No luck. Now the IDLE seems to hang while off the throttle insanely high without the choke on, and the choke will raise it even more.


    I really have no clue what to do. Currently when you start it the idle shoots way up and stays there... Just want this thing to run correctly... Sorry for the long post
    #1
  2. 32x20

    32x20 Been here awhile

    Joined:
    Jul 7, 2012
    Oddometer:
    334
    Location:
    Charleston, SC
    I've got a slant FCR (s model bike) and it did something similar with the high idle. The trick is to adjust the fuel screw and idle screw together. Once you get it right it'll idle fine. As I don't have an e or pipe I can't comment on your jetting. Make sure you don't have so much tension in your throttle cables. Finally, for the bog issue, research the 'Eddie' mod. It involves wiring the accel pump lever so you get an instant squirt.

    Hope this helps get you sorted. The fcr is definitely more finicky than the CV carb.
    #2
  3. sweetwater

    sweetwater Been here awhile

    Joined:
    May 30, 2007
    Oddometer:
    471
    Location:
    Charlotte Metro
    Sierra, you got this man, try the above advice and rock it out.
    #3
  4. BigShooter

    BigShooter Head Flunky

    Joined:
    Jun 28, 2013
    Oddometer:
    210
    Location:
    republic of Texas
    make certain it is get sufficient fuel from the tank as well. in my experience, one reason an engine that will only idle well on choke or stumbles during excelleration is that it is not get good fuel, be it from a lean situation setting of the carb or fuel delivery. do the earlier mentioned as well
    #4
  5. SierraCB

    SierraCB wadahp

    Joined:
    Sep 19, 2013
    Oddometer:
    122
    Location:
    Reno/Tahoe, Nevada
    I think the mixture screw has something to so with it for sure. I need to get one I can adjust with my finger... I did change that last time I had it apart so it could be the issue. Also my idle knob is super hard to turn so it makes it a pita
    #5
  6. SierraCB

    SierraCB wadahp

    Joined:
    Sep 19, 2013
    Oddometer:
    122
    Location:
    Reno/Tahoe, Nevada
    Fuel is definitely good. New petcock and line, nice steady stream.
    #6
  7. bobbed06

    bobbed06 Cavalera Conspirator

    Joined:
    Aug 25, 2010
    Oddometer:
    1,242
    Location:
    That one place......
    You have a 13 year old carb that wasnt the best design to begin with. The slide and body wears over time, which causes the symptoms you mentioned. It also has a anti popping or deceleration diaphragm that goes bad. The FCR also has a non replaceable seal/gasket in the body so it is not advisable to soak these carbs in a tank. Once the slide and body are worn out, you can chase a tune forever, it will never work properly. An upgrade to the FCR-MX carb will be a good idea here.
    #7
  8. SierraCB

    SierraCB wadahp

    Joined:
    Sep 19, 2013
    Oddometer:
    122
    Location:
    Reno/Tahoe, Nevada
    There are people with much older and abused stuff, I think this is unlikely.

    Here's a video. At first it idles okay then a second or two in it kicks up all of a sudden. I've played with the idle and fuel screw, neither do anything to help.

    http://youtu.be/ts84ZjwiAGI
    #8
  9. bobbed06

    bobbed06 Cavalera Conspirator

    Joined:
    Aug 25, 2010
    Oddometer:
    1,242
    Location:
    That one place......
    Check the engine to carb boot for damage/leaks.

    Check the airbox to carb bell boot. This will cause you fits if its leaking.

    Up the pilot jet to a 50 or 52 If I were you I would go ahead and try this. This will mask a worn slide and carb body

    I think I am running a 50 or 52 and a 158 main, but mine is a 434cc/Cams/MRD at sea level with a FCR MX carb. I think my Pilot is still a tad lean.

    Thats all I have for you buddy.
    #9
  10. SierraCB

    SierraCB wadahp

    Joined:
    Sep 19, 2013
    Oddometer:
    122
    Location:
    Reno/Tahoe, Nevada
    Installed the FCRMX to replace my stock FCR as it was worked. Had high hopes that this was the end of working on the bike and I could finally ride it.

    After install I primed the carb, kicked it, and it started right up with the choke. Rode it around a bit and seemed like it was working great. Idled fine, ran great etc.

    Let it sit for a few minutes as I was going to adjust the MCCT and went to kicker it over again and it was a no go. Kicked it a ridiculous amount of times and nothing. Also started to leak when I kicked it out of the float bowl vent tube...
    Both choke on and off. Tried to bump start it and it worked. Seemed to run fine again. Turned it off, went to kick it, nothing. Bumped it again and let it idle for about 5 mins. Temps were around 190 so I figured that it was definitely at operating temperature.

    Turned it off and yep, won't start with the kicker.

    What's going on? I've dumped a crazy amount of money just to get this bike going and I have no luck at all with it. Seems like there is no end in sight whatsoever.

    Also, seems like the counter shaft sprocket is leaking also... sweet
    #10
  11. freewheeler

    freewheeler Been here awhile

    Joined:
    Jul 5, 2006
    Oddometer:
    112
    Sounds like you have tight valves to me ... Check them first before you do any more carb ajustments
    #11