LeapFrog Nitro 4-Tec 3.3TM all-wheel-drive 4809 - Manual (Page 39)

Nitro 4-Tec 3.3 • 39
Troubleshooting Your Nitro 4-Tec 3.3
Engine spins but will not start:
If the engine is spinning but will not start, first check to make sure
that both the motor and glow plug LEDs on the EZ-Start controller
light when the button is depressed. If the glow plug LED does not
light, make sure the blue glow plug wire is tightly connected and is
not damaged in any way. If the wire is good, then replace the glow
plug. It is normal for glow plugs to require periodic replacement. Only
use Traxxas heavy-duty long glow plugs (part #3231).
Check to make sure the fuel is getting to the carburetor. Remove the
fuel line where it connects to the carburetor to see if there is fuel in it.
If not, you may need to prime the engine. Reconnect the fuel line and
then refer to page 27 for instructions on priming the engine.
Check your fuel mixture settings. It may be necessary to adjust the
fuel mixture if the outside temperature or barometric pressure has
changed significantly since the last time the engine was run (see
Fine
Tuning the Carburetor on page 31). Turn the high-speed needle out
(rich/counterclockwise) 1/4 turn, hold the throttle trigger at about 1/2
throttle and try again to start the engine. Once started, retune the
engine for performance (see page 29).
The engine could be worn. If the fit between the piston and sleeve is
loose, compression is reduced and the engine will be difficult to start
when it is warm, and may tend to stall when running and when the
throttle is closed suddenly to idle. Engine life depends on many
factors including fuel type, air filter maintenance, needle settings, and
how the engine was used. For example, if the engine was allowed to
ingest dirt from lack of air filter maintenance or running through
water, then the internal engine components could wear out
extremely fast.
Engine performance sluggish:
Engine performance depends mostly on the fuel mixture settings and
how they compensate for the current atmospheric conditions. Before
you suspect other failures with the engine, richen the high-speed
needle at least 1/4 turn and then retune the engine for performance
(see page 29).
Try a new Traxxas 3231 glow plug. Sometimes a glow plug will work
well enough to start the engine but not be able to deliver the
engine’s full performance potential.
If the fuel mixture seems to be set correctly, make sure the fuel is
fresh. If the fuel is old, or was left uncapped for a long period, then
some of the important fuel components could have evaporated. Try
new, fresh, Traxxas Top Fuel
Check to make sure there is no binding in the driveline that would
cause excessive loads on the engine.