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HELP!!! 3.3 carburetor problems...

Discussion in 'Traxxas Revo' started by ChopSt1x94, Jan 5, 2008.

  1. ChopSt1x94

    ChopSt1x94 RCNT Member

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    I love my revo 3.3 so much and like to run it a lot. Last night during after run procedures, I was spraying WD-40 into the carburetor. It opened with ease and i sprayed it in... I didn't think i put enough in so i figured id open it up again and spray more. The carburetor would not open! Now whenever i turn the car on and press the gas on the reciever to move foward, it doesnt do so. When i brake, the break locks up and doesnt revert to idle. I have no idea whats wrong but assuming it has something to do with my servo. everything is fully charged... any suggestions.
     
  2. jon2

    jon2 Nitro ASSpired!!! Supporter

    Have you checked the throttle linkage? Sounds like you are binding.
     
  3. ChopSt1x94

    ChopSt1x94 RCNT Member

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    This is my first nitro - what does that mean and how can i fix it? Thanks!
     
  4. olds97_lss

    olds97_lss RCNT VIP Supporter

    The shiny wire that goes from the carb to the servo, is it hitting anything? If you take off the little L shaped pivot that connects to the end of that wire and the carb (a single bolt holds it onto the engine mount), then you should be able to slide the carb barrel by hand. If you can't, then your carb is gummed up.

    The stock TRS (throttle return spring) on the revo's was always too stinking strong for the weak servo they use. Your servo may just be dead. You can try and disconnect that spring (without the truck running) and see if the throttle opens and closes (or at least opens) when you apply the throttle via the remote. If it does with the spring detached, then your servo is on it's last leg.

    If you replace the servo, I'd suggest replacing it with something stronger like a futaba S3305. Not a real expensive servo, but it will (or should) be able to overcome the resistance of the TRS better and should last longer since it's a metal geared higher torque servo than what comes on the truck stock. It's actually quite a bit stronger than the steering servos. I ran the S3305 for a long time as my throttle/brake servo on my revo when I had it.

    I completely redid the throttle linkage though as I hated that TRS that's on there...

    The futaba servo is also compatible with the stock horns as traxxas servos use the same output shaft splines as futaba.

    Here's a photo of what I had on mine:
    [​IMG]

    I used this on the end that connected to the L pivot:
    http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD910&P=7

    I used 2mm threaded end push rod for the wire. Found it in the wire rack at my LHS. I can find one specificly on tower...

    And I used typical collars/springs for the servo side.

    This worked a lot better than stock. And it didn't require the stock TRS spring as the spring on the rod itself holds the carb closed and allows for more movement for braking. Also, using little 5x8x2.5 bearings in the throttle pivot made for smoother and longer lasting throttle action.
     
    Last edited: Jan 5, 2008
  5. Cupooterluvr

    Cupooterluvr Hardcore RCNT User

    If you take like 3 or 4 ballpoint pen springs and compress them then it is still pretty strong. If you don't need so much strength for the return then just use 1 or 2. Also is free if you find them around town like I do lol
     
  6. ChopSt1x94

    ChopSt1x94 RCNT Member

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    Thanx guys for the help...i tested the servo by switching the steering channel with the throttle channel on the optidrive it was clear that my servo simply died.I'm going to open up another thread to c which servo i should get.
     
  7. olds97_lss

    olds97_lss RCNT VIP Supporter

    The futaba S3305 isn't bad. I used it with good results.
    (As previously notated in excruciating detail... ;) )
     

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