The Low-Speed Needle
The “low-speed” needle located on the side of the carburetor. It
controls the fuel to air mixture at low throttle settings. There is a
simple way of adjusting the low-speed needle correctly called the
“pinch test.” With the engine at idle, pinch the fuel line and listen to
how the engine speeds up or slows down. If the engine increases
its speed for about 3 or 4 seconds and then loses speed, the
needle is set correctly. If the engine loses RPM quickly, it is set too
lean and the low-speed needle needs to be opened
(counterclockwise) to richen the mixture. Pinch again to check the
mixture. If the engine takes longer than 5 seconds to slow down,
lean (clockwise) the low-speed needle and then pinch again to
check the mixture. Note: Make sure the high speed needle is set
properly before the low speed needle is adjusted.
The Idle Stop Screw
On the front of the carburetor, there is a black screw. This is called
the idle stop screw. This increases or decreases the idle RPM
without changing the fuel to air mixture. The barrel should be
approximately 1.5mm (between 1/32" and 1/16") from fully closed.
Note: This engine was designed to racing tolerances and may
take longer than 5 tanks to fully break-in.
To insure long life and good performance from your DuraTrax .18
engine, you MUST break-in the engine. The break-in period is
critical for long life of the internal parts of the engine. This should be
done over the first 5 tanks of fuel.
Some Things To Remember During Break-In
❏
1. Run with the body off. This will keep the engine cooler.
❏
2. Keep the air cleaner on at ALL times
❏
3. Run on a smooth, hard surface. An empty parking lot
is perfect.
❏
4. Use the same fuel that you will use for normal running.
❏
5. Resist the urge to accelerate and decelerate the
buggy quickly.
❏
6. Break-in puts stress on the glow plug and you can burn it
out during break-in. Make sure you have an extra plug or
two on hand.
❏
7. Do NOT overheat the engine. You can check the head
temperature by using one of the temperature gauges that
are available or by putting a drop of water on the top of the
cylinder head. If the water boils away immediately, shut off
the engine and allow it to cool. If it takes more than 4
seconds to boil away, the engine is at proper running
temperature for break-in.
Before running the engine, read the manual and watch the
engine video that came with this kit.
Fuels
Use fuels that are specially formulated for car
and buggy engines and have a nitro content
between 10-20%.
DuraTrax Red Alert
(DTXP0520) fuel is specially formulated for
R/C car engines like the DTX .18.
There are several simple steps to starting the engine:
❏
1. Install a glow plug. This threads into the top of the cylinder head.
❏
2. Fueling - Fill the tank almost to the top. Leave a little air at the
top of the tank.
❏
3.Prime the Engine (when cold) - Wrap you finger with a shop
towel and place it over the tuned pipe's exhaust exit. Pull the recoil
gently until you can see fuel reach the carburetor (looking through
the fuel tubing). Note: The engine should not require priming when
hot unless you ran out of fuel).
❏
4. Open the high speed needle valve exactly 2 turns out
(counterclockwise) from fully closed. The high-speed needle is
sticking up from the carburetor inside the brass housing. All of the
carburetor settings are adjusted with a flat bladed screwdriver.
❏
5. RTR Version ONLY: Install the included "C" size battery into
the included glow starter as shown.
BREAKING-IN THE ENGINE
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