tmaxx 3.3

[Thrashjavi]

Hey guys I have a problem that I hope someone can answer. When I start my truck it will move slowly forward by itself. if I don't press the brake it will pick up speed continuously. anybody know how I can change that so it doesn't move by itself when it's on? greatly appreciated

 

[spiritdriven7]

Hey guys I have a problem that I hope someone can answer. When I start my truck it will move slowly forward by itself. if I don't press the brake it will pick up speed continuously. anybody know how I can change that so it doesn't move by itself when it's on? greatly appreciated

Try the throttle trim on your radio first. If the adjustment is not enough then you can make idle adjustments in small increments. Seriously...there are a number of fine tuning options...linkage adjustment, low speed needle, the servo end point...etc. if you have the set-up DVD from Traxxas...you have a good tutorial. In it they include an example that sounds like the problem you're facing. Hope that helps.

 

[Thrashjavi]

Try the throttle trim on your radio first. If the adjustment is not enough then you can make idle adjustments in small increments. Seriously...there are a number of fine tuning options...linkage adjustment, low speed needle, the servo end point...etc. if you have the set-up DVD from Traxxas...you have a good tutorial. In it they include an example that sounds like the problem you're facing. Hope that helps.

thanks really appreciate

 

[Nitro4910]

Start by making sure your carb is at the closed idle position when the throttle trigger is in the neutral position.
If that is good your idle too high? If the idle is high, give it 1/16-1/8 turn richer to help drop the idle.
If the idle is good and the wheels start spinning at start up and the engine dies when you apply the brakes then you have either a bad clutch spring or bad clutch bell bearings.

 

[Thrashjavi]

how do you adjust the carb idle position

---------- Post added at 7:06 AM ---------- Previous post was at 7:05 AM ----------

Start by making sure your carb is at the closed idle position when the throttle trigger is in the neutral position.
If that is good your idle too high? If the idle is high, give it 1/16-1/8 turn richer to help drop the idle.
If the idle is good and the wheels start spinning at start up and the engine dies when you apply the brakes then you have either a bad clutch spring or bad clutch bell bearings.

how do you adjust the carb if it is not closed

 

[Nitro4910]

You need to put the throttle trim to the neutral setting first.
If the carb is being held open by the linkage with trim in the neutral position, you then need to loosen the set screw on the linkage stop, move the collar to let the carb close then retighten the set screw in the linkage stop.

Below circled in red, is the linkage stop I'm talking about.

When the linkage is set correctly and the idle gap is set to 1mm the carb should look about like this with no throttle input.

 

[Thrashjavi]

no to both questions

 

[Nitro4910]

So the carb is closed like it's supposed to be at idle, and the idle gap is good?

 

[TheUnownKitty]

Hello I kinda have the same problem with my 4 tec I have tried everything like all the needles and stuff but it just wants to take off. I don't know why please help

 

[Rolex]

Check your clutch. If the springs are weak they will engage at a low RPM or they will stay engaged as soon as you start the engine.

 

[TheUnownKitty]

Okay that's what I was kind figuring thanks

 

[Thrashjavi]

So the carb is closed like it's supposed to be at idle, and the idle gap is good?

this is how open mine is

 

[Nitro4910]

Push the slide in to be sure it's sitting against the idle gap screw for an accurate look at the idle gap.
1mm is where you should set it for a starting point, most set it to 1mm & leave it set there.
To set it at 1mm, you can use the smooth portion of a # size 60/61 drill bit, put it between the slide & the carb housing, push the slide all the way in.
Then turn out or in the Idle Gap screw till the slide just touches the drill bit shank, it's the set.
Now it's time to retune, start at 4&flush at a half tank of fuel.

There's a great tuning guide sticky here on the forum or you can use the ERCM guide.
https://www.rcnitrotalk.com/forum/showthread.php?t=60832
http://www.extremercmods.com/content/tuning-popup.html

 

[hotrodrob]

Totally agreed with nitro4910..
All those sand particles in your carb throat are going to be the death of this engine, not trying to bash you or anything but it looks like you need to imply better air filtration,..whether it be maintenance or a tighter seal, ect