Nitro rustler 2.5r

[int3gra4life]

Hey everyone well i recently purchased a new engine which is the 2.5r ok well i thought i can just put it in and thats it but the low speed needle is facing downward which means i cant connect the piece to it for the throttle i tryed unscrewing it and turning it around but you cant it dont screw back in. How do i go about connecting it Thanks in advance appreciate it if u can help :).

[z3usX5]

not sure what your asking about? you talking about the linkage on the carb?

[cbonner99]

pics would help us help you too.

[int3gra4life]

No i am talking about the low speed needle it is facing downward but it needs to be facing upward so it connects.

http://i24.photobucket.com/albums/c22/johnownsall2/9043b0a3.jpg

[ottoseller]

look at the top and you will see a set screw, loosen with allen wrench
and turn around as needed.:thumbs:

[int3gra4life]

The top of what? of the needle?

[BIG RED]

using a 1.5mm hex wrench,loosen the grub screw, rotate the arm to where you need it, then re-tighten the grub screw :thumbs:

[int3gra4life]

Ok i got it thanks alot :). i think ima have to take it in cuz the throttle isnt right like it gets stuck and what not and as soon as i get it started it screams like no tommorow ima have them just tune everything because i am givin up on this thing i spent 2 weeks tryina get it right still cant do it.

[cbonner99]

The best thing to do is find someone else near where you live that has nitro RC experience and get with them to give you pointers. We can help here but having someone right next to you to ask questions of really helps.

Don't give up, most of us have blown up a motor or something else due to our own stupidity.

[BIG RED]

sounds like you have your idle needle in way to far(the smallest needle on the carb, see pic) take off your air filter and see how far the carb slide is open when you push the slide in. you should only have about a 1mm gap or so

[int3gra4life]

well how far does it have to be out cuz i took it out so the head of the screw is hangin out but it still does it?

[BIG RED]

go back to stock needle settings then, they are in your manual, it's probably very lean if it is still revving like that

[joocey2002]

Tuning the TRX 2.5 for Best Performance
The engine’s performance depends on the fuel mixture.Turn the
mixture needles clockwise to lean the fuel mixture and
counterclockwise to richen it. Leaning the fuel mixture will
increase engine power up to the engine’s mechanical limits.
Never run the engine too lean (not enough fuel flow). Never
lean the engine until it begins to cut-out or stall. Leaning the
engine beyond the safe allowable limits will result in poor

performance and almost certain engine damage.
Indications

of an overly lean mixture include:


Cutting out or sudden loss of power during acceleration.


Overheating (temperature beyond 270° F at the glow plug)


Little or no blue smoke coming from the exhaust.


If any of these conditions are present, stop immediately and


richen the high speed mixture 1/4 turn.The engine will


probably be slightly rich at that setting and you can then retune


for performance. Always tune for performance by starting rich


and moving leaner toward the ideal setting.Never try to tune


from the lean side.There should always be a light stream of blue


smoke coming from the exhaust.


Before you begin tuning, the engine should be warmed up to its


normal operating temperature and running slightly rich. All final


tuning adjustments must be made to the engine at its normal


operating temperature.You can tell the engine is running rich


by noting any of the following:


Sluggish acceleration with blue smoke coming from


the exhaust.


There is unburned fuel spraying from the exhaust tip


Leaning the high-speed fuel mixture increases performance


High-Speed Fuel Mixture Adjustment


With the engine warm and running at a rich setting, gradually


lean the high-speed fuel mixture in 1/16 turn increments.Make


several high-speed passes with the Nitro Rustler after each


adjustment to clear out the engine and note any change in


performance.The TRX-2.5 is extremely powerful. Remember to


apply the throttle gradually to prevent wheelies or loss of


control. Continue this procedure until one of the following


conditions exist:


1.


There is no longer any performance improvement

2.


The engine begins to cut out at high speed (Danger!)

3.


There is a sudden loss of power during acceleration (Danger!)

4.


The engine begins to overheat.Symptoms of

overheating include:


Steam or smoke coming from the engine (not exhaust)


Hesitation or stalling during acceleration


Popping or clattering sound when decelerating


(detonation)


Fluctuating idle speed


Temperature measurement above 270° F at the glow plug


If any one of the above conditions occurs, the fuel mixture is


already past the maximum safe lean setting. Richen the fuel


mixture to the optimum setting by richening the high-speed


needle at least 1/8 turn counterclockwise and retest.This setting

will extend engine component life.


35

[joocey2002]

Low-Speed Fuel Mixture Adjustment


The low-speed mixture is always set after the high-speed needle


is correctly adjusted.The low-speed mixture will be set using the


pinch test.


1.


Once the engine is warm, do several high-speed runs to

confirm that the high-speed needle is set correctly.


2.


Bring the vehicle in and pinch closed the fuel line going into

the carburetor.The engine should run for 2-3 seconds, speed


up, and then die.


3.


If the engine runs longer than 3 seconds, then lean the

low-speed needle 1/16 turn, make several more highspeed


runs, and retest.


4.


If the engine dies immediately without speeding up, then

richen the low-speed needle 1/8 turn, make several more


high-speed runs, and retest.


When the low-speed needle is set correctly, the engine’s throttle


response should be very quick, possibly even to the point of


making it difficult to keep the Nitro Rustler from doing a


wheelie when you accelerate!


Idle Speed Adjustment


Once the high and low-speed mixtures have been set, reduce


the idle speed to the minimum reliable idle speed. Remember,


this adjustment should be made while the engine is running at


normal operating temperature.


1.


Turn the throttle trim on the transmitter so that the brakes

are applied.This ensures that the throttle slide is resting


against the idle adjustment screw.


2.


If necessary, remove the air filter to gain access to the idle

adjustment screw.


3.


Turn the screw counterclockwise to reduce the idle

speed, or clockwise to increase it.The idle speed should


be set as low as possible while still maintaining reliable


running characteristics.


4.


Reset the throttle trim on the transmitter

Fine-Tuning the Carburetor


After fine-tuning your TRX 2.5 racing engine at the end of the


break-in procedure, no major adjustments to the fuel mixture


are usually necessary.Make note of the temperature, humidity,


and barometric pressure at the time you finished fine tuning


your carburetor. Current weather conditions can be found


online from national websites, local TV news websites, and


Television.This information will be considered your baseline


setting.You may need to adjust your carburetor needles to


compensate for changes in temperature and barometric


pressure (air density) from day to day.Generally, you’ll need to


richen the fuel mixture when the weather is colder than your


baseline temperature and the air density is higher. Lean the fuel


mixture when weather is warmer than your baseline


temperature and the air density is lower.The chart below


provides general guidelines on how weather conditions affect


air density when they move higher or lower than your baseline


setting (see page 28 for detailed info on how air density affects

mixture settings).

[joocey2002]

got that from traxxas web site
and this

If your factory
preset carburetor
adjustments have
been tampered with, use
the following settings: set
the low-speed needle so
that the screw head is flush
with the end of the slide.
Set the high-speed needle
to 4 turns out from closed.
Always use the factory
settings for initial starting.
Only use these settings
when the factory settings
have been lost.

[BIG RED]

if all else fail, take it to your local hobby shop and get it fixed. If the guy is cool, throw him a tip, us hobby shop mechanics love that:thumbs:especially if the engine gives us a hard time(most traxxas engines do)

[born420]

yeh because we have none of these good mechanics here where i live and im noob i messed my carb too lol and just said screw it i shipped it off to get a 3.3 from origionally having a .15 in my pede lol power im also setting up my parts wish list. im converting it all over to t6 and i was wondering if you can put a second speed on the stock pede gear box or what ever it attaches too j/w

[BIG RED]

I think the newer traxxas engines have an instructional DVD on engine break in and tuning, watch it and see if that helps you out.

[joocey2002]

be prepared for some major power with that 3.3 compared to what you had(1.5). you'll have a hard time keepin the front end down!!!:rock:

[born420]

oh imhave fun though thats all that matters haha cant wait supposed to be here between it outmonday (tomorrow) an friday if not i gotta call traxxas, they wouldnt give me a trackin # wtf they told me if it dont arrive by the end of the month give them a call, why couldnt they just give me a # too like i provided all my info for them to reference oh well just gonna have to wait