How long does it take...
Results 1 to 7 of 7
  1. #1
    Senior Member bsilver's Avatar
    Join Date
    Dec 2007
    Location
    Mesa, AZ
    Posts
    166

    Thumbs up

    So, I'm at the start of the WORCS race this weekend. I've been idling the bike off and on for about half an hour. It's hot enough to where you can't touch the thing. Then we stage, and they signal to cut the engines...as usual. This lasts a couple minutes as they talk to all the guys on the six different rows at the start. Then it's fire 'em up, and we go.

    Now, the flag drops, and I get a good jump...for about 5 feet. Then the motor has got nothin!!! Only low rev power. Nothing in the mid or top. I gotta short shift to not get completely left behind! After a couple of corners, maybe 30 more seconds or so, everything is fine. Screams like normal, bottom to top. But 30 seconds is a long time to have limited power in a race scenario! AND...this keeps happening. This is like the third time. I'm tired of playing catch-up when I could be owning the holeshot.

    So, it seem like the engine is not warmed-up enough at the start of these things. My question is...how the hell do I get it that way??? How long do I gotta idle this thing before it's at "race" temperature? Have I got a tuning issue or something? MX season is two months away, and that kinda thing will KILL me in a 4 lap moto. These WORCS races are an hour, so there's time.

    Any ideas guys?
    '88 TRX250R - FMF "fatty" pipe and "Q" silencer. 38mm Air Striker carb. 86 style piston w/ MX ported 88 cylinder. 88 rod and spacer plate. ESR billet head w/ 23cc dome. Boysen Rad Valve. Elka Elites front and rear. Fullflight +3 +1 a-arms. Lonestar +4 axle. Fullflight MX bumper. AC Blackline Propegs. Fullbore plastics. DFR "gripper" seat. Tag X5 bars. Streamline SS +3 lines. PRM radiator shrouds. MMF full belly skid. Powermadd handguards. Pro Design tether.

    http://img1.putfile.com/thumb/2/5604032542.jpg

    http://www.arizonaquads.com/images/b..._holeshot1.jpg

  2. #2
    Super Moderator C-Leigh Racing's Avatar
    Join Date
    Dec 2007
    Location
    Nashville NC
    Posts
    4,273
    Blow heater blowing on the engine while its sitting at your pits, sounds like a carb problem though.

    Neil


  3. #3
    Senior Member 312R1's Avatar
    Join Date
    Dec 2007
    Location
    Port Matilda Pa
    Posts
    1,257
    I'm with Neil...It sounds like when it's just sitting the idling it loads up...I would check the jetting on the pilot and air screw.
    Laeger Pro-Trax CR500 link 250R

    08 Sponsers
    BVC Racing
    Clegg's Innovations
    Duncan Racing
    Galfer
    McCoy Motorsports
    Mrcycles

  4. Remove Advertisements
    TRX250R.net
    Advertisements
     

  5. #4
    Senior Member bsilver's Avatar
    Join Date
    Dec 2007
    Location
    Mesa, AZ
    Posts
    166
    Ok. I actually had thought of the "loading up" thing. Someone else suggested a few good revs before the gate drops to see if it "cleans out" to test that theory. Plug looks a bit rich too, so maybe this all fits together. Something to look into anyway.
    '88 TRX250R - FMF "fatty" pipe and "Q" silencer. 38mm Air Striker carb. 86 style piston w/ MX ported 88 cylinder. 88 rod and spacer plate. ESR billet head w/ 23cc dome. Boysen Rad Valve. Elka Elites front and rear. Fullflight +3 +1 a-arms. Lonestar +4 axle. Fullflight MX bumper. AC Blackline Propegs. Fullbore plastics. DFR "gripper" seat. Tag X5 bars. Streamline SS +3 lines. PRM radiator shrouds. MMF full belly skid. Powermadd handguards. Pro Design tether.

    http://img1.putfile.com/thumb/2/5604032542.jpg

    http://www.arizonaquads.com/images/b..._holeshot1.jpg

  6. #5
    Senior Member 2R's's Avatar
    Join Date
    Dec 2007
    Posts
    3,565
    1st post describes all the symptons of a poorly tuned carb..
    own a shop manual for the R ?...read ,reread learn "carb theory"

    the problem may or may not be only in the size of main jet ...

    "Only low rev power. Nothing in the mid or top"



    type of plug///plug gap ?



    she's a MX racer
    http://mxptv.com/video/rider-session...loretta-lynns/

    http://www.photoreflect.com/pr3/thum...aspx?e=5567552
    http://rides.webshots.com/album/573945126OHEsjN

    "Those who dance are often called crazy by those who cannot hear the music"

    "the man who follows the crowd will usually get no further than the crowd
    the man who who walks alone is likely to find himself in places no other has been before" A Einstein

  7. #6
    Moderator BLACKeR's Avatar
    Join Date
    Dec 2007
    Posts
    413
    it does sound like its loading up. you could try some high revs mixed in the clear it up, but i suspect a smaller jet or air screw adjustment will fix it completely.

  8. #7
    Senior Member 86 Quad R's Avatar
    Join Date
    Dec 2007
    Location
    Stixville, MS
    Posts
    190
    you deffinately need to tune the carb. your pilot may be a tad rich, the pilot screw may need a bit of adjusting, the float could be a tad bit off or a combination of all the above.

    remember that any 2-stroke(even jetted/tuned spot on) will tend to load up some at a idle. i would spend the time it takes to make sure all is well with the pilot circuit and the main for that matter. afterwards test things out in different scenario's (as if you were at a track) and see what happens. almost always, its best to "clear it's throat" (few good snorts of the throttle) before it's time "to bark" (launch).
    >>Randy<<

    250R&#39;s...... "they gots bite wiff dat bark !!!"
    R&#39;s are fo sand bars.....


    http://www.imagestation.com/picture/...0/e8f2130c.jpg


 

Remove Ads

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •