hennytime

Ok, I'm having some issues getting my car to just idle. This is my first time playing with a rc car and ive got it to the point where it either just stalls after about 5 seconds or it wants to run away from me out of control and obviously is idling way too high. This is also my first time using carburetors but i do mod cars quite a lot. Anyways, i took a pic of the carb fully closed and my buddy who has a few years experience running rc cars said it has too much of a gap and said it should be no more than 1mm.

Here is the pic, and basically I'm asking what you guys think my issues might be. everything came from the factory as such. thanks in advance, Ryan.

ehroof

thats too open bro, you have to trim it back to close it, use the trim control on the transmitter, hit the brake and see if it closes and has the 1mm gap.

rclynx

Man that looks like its ready to swallow a horse

Redharris

This is the way Ive been doing it.
I take OFF the linkage and close the carb manually and then adjust the Idle Screw to about where it should be, (about 1 mm opening).
Then I turn the Radio on and center the servo. Then I re-install the linkage and adjust it to the point where, when I take my finger off the throttle, the carb setting is at neutral (no brake/an no throttle). Now I start the car (use a bit of throttle trim if you need to) and adjust the Idle screw for Stationary idle.
Now , the Carb will NEVER close all the way when you brake or stop. Works for me.....

hennytime

ya i took off the linkage just at the small arm that connects the throttle body esque part of the carb and the servo that is connected with a "medium" sized small alan wrench (i'm used to working on ls1's) and i didnt try to move it back too far but it seems that is the farthest back it will go. Think i should take off the carb all together and try to adjust it there? also the little screw in the carb, near where the arm connects to it, should it be backed all the way in or all the way or or should it not matter? Am i missing some small menial part that i am overlooking? again thank you all for the help

jj1987

I saw the car, when everything is physically disconnected, we can't get the carb to go any tighter. I've got 2 RC car's myself, and have broke or fixed basically everything on the two of them, but I can't for the life of me figure out why the carb wont close any further.

Redharris

I dont think you're missin anything. The carb looks complete in the pic you posted.
Find the Idle screw. Its the small Black screw directly in front of the carb barrel (between the Carb barrel and the Flywheel.)
Turn the Idle screw Counter Clockwise (dont take it all the way out!) one full turn and manually close the carb. You should see that the carb closes further now. repeat this process till you get the setting you are looking for.
The Idle screw is nothing more than a Mechanical LIMITER for the part of the carb that slides open n closed (throttle body?) when you actuate the arm.

The little screw in the carb ( if I am understanding you correctly) is the Low Speed Needle (LSN). Thats the screw that LOOKS like it holds on the Carburetor Arm (thats not what it does tho). It should be screwed out so that it is Flush with the Silver ring that surrounds it.

The big Brass screw is the High speed needle (HSN). It should be screwed in GENTLY till it bottoms out, then screw it out approx 3 turns.

HSN out 3 turns,
LSN flush with the silver ring
Idle screw adjusted so that Carb is open 1 mm, when you Manually close it.
Now you hook up your linkage, You will have to fiddle with it (we all do) to get it to work just right. Dont be afraid to take the Servo Horn off and reposition it to get everything lined up.

When you finish, it should work like this: With the Radio n servos ON
Full throttle on the radio = Carb Wide OPEN
Finger OFF the throttle trigger = carb at idle position ( it cant close MORE cuz the idle screw is stopping it at Idle position)
Full Brake on the radio = Carb didnt move from idle position, but the Brakes are now actuated

Redharris

If you took the Idle screw completely out or un- screwed it too far then the Idle screw may have "Slipped its Groove".
If the throttle arm seems like it wants to "Pull Out" then you have to reseat the Idle screw in its Slot. SLide the throttle arm in and out and gently screw in the Idle screw until you feel it slip into its groove ( you will know when it happens)

If all else fails, then take it apart and see what is going on. If you are careful (and mechanically inclined), you will not hurt anything. You say you have worked on a lot of cars, then you have probably done this process already. Honestly though, I really dont think there is any thing wrong. I think it is just Mis -adjusted.

jj1987

I've honestly never had to turn an idle screw more than 1 turn from factory, so that could be the issue. I've got the car at my house, so I'll try that for him today.