Car runs full throttle when starting

[ramsay]

Hi i have bought a brand new Nitro rc buggy and iam a total novice to these.
I have no problem starting the engine though as soon as it starts the engine starts full throttle. I have read that i must adjust the idle control screw so that the gap is around 1mm. I have tryed this and this has no effect what so ever. I have also tryed to adjust the throttle trim on the remote this also has no effect what so ever.
When the engine starts if i hold the car the engine keeps running as soon as i pick the car up it hits full throttle ?
In my pictures the gap is allot bigger than it should be i just put it back to the way it was when i took it out the box.
Could there be any other settings on the remote thats making the engine run at full throttle. ?
Any help with this would be great.
Thanks

 

[madd802]

disconnect the linkage at the throttle servo and then try starting it... sounds like the servo is not centered

 

[ramsay]

Thank very much for your response sorry for not been very technical minded with these cars would it be possible to upload a picture of throttle server linkage so iam sure it's the right thing iam disconnecting.
Thanks for your help.

 

[madd802]

on this picture the silver rods. The top one is your brake linkage and the bottom one is your throttle linkage where they meet the black t bar on the black servo on the left side of the picture take the Philips screw out of the center and then try and start it

 

[ramsay]

Took the Philips screw out of the black t bar then started the car again same thing again car hits full throttle.

 

[madd802]

make sure the linkage is pushed all the way in whatever direction keeps the carb closed

 

[Snook Man]

You need to make sure the throttle valve is closed to 1mm or less before you even try and start it again.
With the air filter removed so you can see in the carb disconnect the throttle linkage from the servo horn (plastic piece that attaches to the top of the servo). Can you close the carb valve by hand to the 1mm gap? If not you need to adjust the idle gap screw counter clockwise until you can. Once you set the idle gap you will not have to fool with it much anymore. After you have the idle gap set reinstall the linkage to the servo horn and then remove the entire horn from the servo leaving the linkage attached to the horn. Turn on the electronics/transmitter and receiver. Set the throttle trim on the receiver to “0”.
With electronics still on, hold the throttle valve closed to the idle gap and install the servo horn back on the servo making sure that any springs on the linkage will apply some pressure to the throttle arm to hold it against the idle stop.
Once you have the horn reattached you should then gain back control of the throttle trim and be able to fine tune the linkage with the transmitter.
Before starting, make sure you have full control of the throttle valve, meaning it should be completely against the idle gap screw with the 1mm or less gap without any input from the transmitter. The valve should also open full to wide open throttle and immediately return to the idle gap once you release the throttle trigger. Once the throttle is working as it should you should then test the brake to see if it needs a linkage adjustment before a powered test run.

 

[Nicky P]

I actually had this same exact problem! I have a Duratrax 835b and the same thing happened. I took it to my closest hobby shop and my low speed needle was WAY to lean. What you need to do, is start the car and imeadietly start richening the low speed needle until it stops. The worker did it to mine while it was off, but he was an expert, so I would have done it with it on. Also, you need to have your carb set at 1mm because with it as far open as it is, that could be the case. Try closing the carb to 1mm before leaning out the low speed needle.

 

[Childresshunt]

I actually had this same exact problem! I have a Duratrax 835b and the same thing happened. I took it to my closest hobby shop and my low speed needle was WAY to rich. What you need to do, is start the car and imeadietly start leaning the low speed needle until it stops. The worker did it to mine while it was off, but he was an expert, so I would have done it with it on. Also, you need to have your carb set at 1mm because with it as far open as it is, that could be the case. Try closing the carb to 1mm before leaning out the low speed needle.

Leaning the lsn raises the idle speed. If he brought your idle down with the lsn he richened it not leaned it

 

[Nicky P]

my bad. Thank you for correcting me.

 

[Childresshunt]

No biggy man thats what other people are here for everyone makes mistakes

 

[Nicky P]

Absoloutly (I can't spell) I'm glad I found this website.

 

[synnyzter]

Let us know if you resolved this, I am curious...

 

[ozziii]

Before changing any needles make sure your idle gap is 1mm or less, .8mm would be better. Make sure your servo is centered & put servo arm on so carb is fully closed with servo in neutral centered position. Moving servo arm by hand, make sure the linkage is set right & is opening & closing the carb throttle properly. Carb should be fully closed when servo is in neutral position, only open the .8-1mm idle gap.
You will then have to start the engine to see what happens, hard to say if its to lean if idle gap, servo & linkage is set up wrong, get them right & test.