NITRO 4-TEC 3.3 • 33
If the engine is worn or
damaged enough to require
replacing the piston,
sleeve, or connecting rod,
consider exchanging your
old engine for a brand new
engine under the terms of
the Traxxas Lifetime Engine
Replacement Plan (ERP).
It could save you time and
effort. Details are in your
model’s documentation
package.
The TRX 3.3 Racing Engine
is designed to be easy to
rebuild. Critical engine
components such as the
crankcase, crankshaft, and
engine bearings are made
to extremely high quality
standards and should under
normal circumstances
outlast multiple sets of
pistons, sleeves, connecting
rods, and wrist pins
(reciprocating assemblies).
It could be more economical
for you to continue to use
your good bearings and
crankshafts, and simply
replace the reciprocating
assembly as needed. Engine
assembly is not difficult and
replacing the reciprocating
assembly does not require
any special tools or skills.
Your Nitro 4-Tec requires timely maintenance in order to stay in top
running condition.
Neglecting the maintenance could allow dirt,
deposits, and moisture to build up inside the engine leading to internal
engine failure.
The following procedures should be taken very seriously.
After each hour of running:
• Clean and re-oil the air filter. The instructions for this procedure are
on page 19.
We cannot stress enough the value of cleaning your air
filter at the scheduled intervals.
The cleanliness and condition of your
air filter directly influences the running life span of your engine.
Do not
skip air filter maintenance!
• Clean the outside of the engine of accumulated dirt, oil, and grime.
Accumulated grime will decrease the engine’s ability to cool itself.
• To maintain optimum radio system performance, replace alkaline
receiver batteries after each hour of runtime. When using the RX Power
Pack (part #3037), recharge the battery after every hour of runtime to
maintain optimum radio performance.
• Tighten the wheel nuts (especially on the left side). Use the included
8mm wheel nut wrench.
After each running session:
• Perform after-run maintenance on the engine. This clears the engine
of destructive moisture and other corrosive deposits. This is
extremely important for the life of the engine. Read on for after-run
maintenance procedures.
• Inspect the gears for wear, broken teeth, or debris lodged between
the teeth
• Inspect the vehicle for obvious damage or wear. Look for:
Other periodic maintenance:
• Connecting rod: The connecting rod should be replaced when the
piston and sleeve are replaced. Also replace the piston wrist pin and
G-clip whenever the connecting rod is replaced. As with other internal
engine components, connecting rod life depends engine’s usage and
the quality and frequency of the engine maintenance. Inspect the
connecting rod after 3-gallons of fuel have been used.
• Piston/sleeve: The life of the piston and sleeve will vary greatly with
how the engine is used and maintained. The piston and sleeve should
be replaced when they no longer seal effectively (loss of compression).
Symptoms include the engine being difficult to start
when warm, stalling when warm, and stalling when
throttle is suddenly closed to idle. Replace the wrist pin
and G-clip whenever the piston and sleeve are replaced.
After-run Procedure
You must perform after-run maintenance on your Traxxas
engine whenever the model will be stored for longer than
a few hours. Taking the time to prepare your engine for
storage will reward you with longer engine life, easier
starting, and better performance.
When a nitro engine is shut off, some excess unburned
fuel remains in the engine. The methanol in model
engine fuel is hygroscopic, which means it easily attracts
and absorbs moisture. This moisture can cause rust and
corrosion on the steel engine parts (crankshaft, bearings,
wrist pin and starter shaft) if the fuel is not removed from
the engine. There are after run oil products available from
your hobby dealer or you can use WD-40
™
, a common
household lubricant. To ensure your TRX 3.3 Racing Engine is protected
from internal corrosion, use the following procedure:
1. Whenever possible, shut off the engine by pinching the fuel line closed.
This allows most of the excess fuel to be consumed by the engine. Be
sure the throttle is in the idle position. You may have to pinch the fuel
line closed for several seconds before the engine stops.
2. Completely empty the fuel tank. Use your fuel-dispensing bottle to
suck out the old fuel. Do not mix the old fuel with your fresh fuel
supply. If you leave fuel in the tank, transporting or handling your
Nitro 4-Tec may cause fuel to run into the engine.
3. With the fuel tank empty and the throttle at the idle position, try to
start the engine. The engine will most likely start and run for a few
seconds as it uses up any fuel remaining in the engine and fuel lines.
4. Once the engine stops, clean the outside of the engine with
compressed air or spray motor cleaner. Once the engine is clean and
dry, remove the glow plug power wire, glow plug, and air filter.
5. Open the throttle fully and spray a one-second burst of WD-40 into the
carburetor and into the glow plug hole (Caution! Wear safety glasses to
prevent spray from getting into your eyes). If you are using after-run oil,
follow the manufacturer’s instructions.
6. Place a rag or paper towel over the engine to catch any WD-40 or
after-run oil that may come out the carburetor or glow plug hole.
MAINTAINING AND STORING YOUR NITRO 4-TEC
16
1. Loose or missing screws
2. Cracked, bent, or
damaged parts
3. Cut or loose wiring
4. Cut or kinked fuel lines
5. Signs of fuel leakage
