Traxxas T-Maxx 4910 Owner's Manual page 32

The TRX 2.5 Racing Engine
Breaking in Your TRX 2.5 Racing Engine
See Important
Points to Remember
The TRX 2.5 uses a ringless, aluminum-brass-chrome (ABC)
on page 5 for other
piston/sleeve construction.This type of engine design relies on a
precautions.
very precise running fit between the piston and sleeve for cylinder
sealing. Engine break-in is necessary to allow the piston and
sleeve to develop an extremely precise fit and optimum cylinder
Never run your
sealing. Therefore, proper engine break-in is critical to achieving
T-Maxx indoors.
the fastest, most reliable engine performance.
Since the TRX 2.5
engine exhaust fumes are
Allow yourself about 1 to 1
harmful, always run your
procedure.The engine break-in period will take 5 tanks of fuel in a
T-Maxx outdoors, in a well-
T-Maxx.The break-in time is not the time to impress your friends
ventilated area.
with your new T-Maxx. You must wait until the engine is fully
broken in before attempting sustained high speed running.
Patience and careful attention during break-in will reward you with
Your TRX 2.5
the best-performing TRX 2.5 possible.
engine doesn't
usually require
During break-in, your engine may appear to malfunction with
priming. If you do need to
symptoms like stalling, inconsistent performance, and fouled glow
prime your engine, watch
plugs.These are simply the normal "break-in pains" engines
the fuel line carefully to
sometimes go through.They will disappear once your engine is
avoid flooding your engine.
fully broken in. Many owners report not experiencing any of these
See page 43 for
symptoms with the TRX 2.5. We recommend to go ahead and
information on clearing a
replace the glow plug with a new one after the engine break in
flooded engine.
procedure.
Engine Break-in Procedure
Your carburetor is
The focus during break-in is to vary and limit the engine speed.
pre-set at the
This will be accomplished by accelerating and stopping at different
factory to give the
rates for the first 5 tanks of fuel. As the engine begins to break-in,
correct air-to-fuel ratio and
the duration and intensity of the acceleration will gradually
idle speed for engine
increase. Sustained high-speed running is not permitted until the
break-in. Do not adjust the
6th tank of fuel. Perform the initial break-in on a large, flat, paved
carburetor unless you
surface. Apply all throttle and braking actions gently. Abrupt
observe a poor running
acceleration or braking could cause the engine to stall
condition that requires
unnecessarily.
correction.
32
1 / hours to complete the break-in
2
Special break-in fuels are not recommended. Use the same fuel
you plan to use everyday.
If possible, avoid breaking-in the engine on extremely hot or
cold days.
Pay careful attention to the fuel level. Do not allow the fuel tank
to run completely empty. An extremely low fuel level causes
the mixture to run too lean.This could result in a burned glow
plug or extremely high engine temperatures.
Keep extra glow plugs handy (Traxxas part #3231).The break-in
process can cause deposits to form on the plug leading to plug
failure.
Follow the instructions exactly for each of the first 6 tanks of fuel.
Starting Your TRX 2.5 Racing Engine for the First Time
Before you start your TRX 2.5 engine for the first time, make sure
you have read all instructions and precautions in this manual. Pay
close attention to the tank-by-tank break-in instructions in the
next section, and make sure you have read and understood
them before you run your engine.
Your engine must be at room temperature (70°F or 21° C) or
above the first time you start it. If it's cooler than room
temperature outside, keep your T-Maxx indoors until you're ready
to start it, then take it outside.
1. Turn on the radio system according to the instructions on page
18.
2. Make sure the throttle is in the idle position.
3. Connect the EZ-Start controller according to the instructions on
page 31.
4. Press the starter button and watch for fuel moving through the
fuel line up to the carburetor.Watch closely! The fuel moves very
fast. If the fuel doesn't move through the line within 5 seconds,
prime the engine by briefly (one or two seconds) covering the
exhaust outlet until the fuel is just visible in the carburetor fuel
line. Watch carefully! If the engine is primed too long, it will
flood with fuel and stop turning.
5. Once fuel reaches the carburetor, the engine should quickly start
and idle.
6. Disconnect the EZ-Start controller from the model.
7. Proceed with the engine break-in.
If your engine doesn't start, see Troubleshooting Your T-Maxx
on page 42.