Team Losi Losi Mega Baja Operation Manual page 3

Required Equipment
You will need the following items to operate your new Mega Baja.
8 AA Alkaline batteries for the transmitter
Losi® Nitrotane™ 20% Sport Fuel. (LOSF0020 or LOSF0120) This is the only fuel that supports the engine warranty.
Fuel bottle (LOSB5201)
Optional: Rechargeable Glow Ignitor (LOSB5221)
Tools You Will Find Handy
In addition to the tools included with the Mega Baja, you will find the following both useful and in some cases necessary.
Small flat blade and Phillips screwdrivers
Needle-nose pliers
Quality .050", 1/16", 5/64", 3/32", 1.5mm and 2.5mm hex (Allen) drivers
Engine Break-In and Adjustments
Breaking in your new engine is critical for proper performance. Failure to follow the break-in procedures can cause
damage and shortened engine life. During break-in and when running, always use Losi Nitrotane 20% Sport Fuel.
Although the carburetor is preadjusted at the factory, you must be familiar with the following adjustments and
break-in procedure. If you change fuel or run in dramatically different environments (hot/cold, high/low elevation, etc.)
you will probably have to adjust at least the high speed needle to prevent overheating and maintain proper
performance. Never, under any circumstances allow the engine to rev freely with the wheels off the ground.
Break-In Procedure
1.) The first three tanks of fuel should be run with the high and low speed needles noticeably "rich" (see explanation
below). There should be a slight sluggishness and thick smoke when accelerating with the smoke decreasing as the model
gains speed. At speed, there should still be a noticeable trail of smoke from the exhaust pipe. Run the Mega Baja on a flat
surface in an oval pattern. Ease into the throttle as you accelerate on the straight sections, easing off as you approach
turns—letting the model roll through the turn before easing back on the throttle. This will also allow you to get a feel
for the steering response and handling characteristics of the model.
2.) You can also break in the engine by placing the model against a wall or fixed object and allow the engine to idle
through two full tanks of fuel. You may have to lean the low speed mixture (slightly) as noted below.
Understanding "Rich" and "Lean" Fuel Mixture
Adjusting the carburetor is one of the most critical facets of running a nitro powered R/C vehicle. The fuel mixture is
referred to as being "rich" when there is too much fuel and "lean" when there is not enough fuel for the amount of air
entering the engine. The amount of fuel entering the engine is adjusted with high and low speed threaded needle valves.
The low-speed needle is located in the front of the moving slide. The high-speed needle sticks straight up at the back of
the carburetor. Both feature a slotted head that is used as a reference and receptacle for a flat blade screwdriver for
adjustments. The mixture is made richer by turning the needle counterclockwise and leaner by turning clockwise. An
overly "rich" mixture will yield sluggish acceleration and performance with thick smoke from the exhaust. A "lean" mixture
can cause the engine to hesitate before accelerating or, in some cases, to lose power momentarily after the initial acceleration.
A lean mixture also makes the engine run hotter than desired and does not provide enough lubrication for the
internal engine components, causing premature wear and damage. It is always advisable to run the engine slightly rich
and never lean to avoid overheating and possible damage.
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