Nitro Rustler
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Winter Break-in Tips
During the break-in process, the piston and sleeve wear into
each other to form a precise fit. The engine needs to heat up to a
temperature around 200 to 215 degrees to allow the piston and
sleeve to achieve this fit properly. A precise fit between these
two components is critical for proper compression, and optimum
performance. If the engine runs too cold during break-in, the piston
and sleeve will not expand to their appropriate sizes for break-in, and
this can lead to premature wear of these components. This wear may
not become apparent until after winter has past, and the engine is
operated under warmer running conditions.
Warm the engine to approximately room temperature by removing
all fuel and storing the vehicle inside at room temperature until just
before starting the engine. An extremely cold engine can become
difficult to start.
After the engine is running, it is important to keep the temperature
of the engine up around 200 to 215 degrees during break-in. In
weather below 45 degrees, the TRX 2.5 Racing Engine will tend
to run at lower temperatures between 160 to 180 degrees (when
tuned at proper break-in mixture settings). This is too cool for break-
in. Do not lean the fuel mixture to increase engine temperature!
This will also decrease lubrication and cause your piston/sleeve to
wear prematurely.
Wrap the cooling head with a paper
towel, clean rag or sock to help
keep the engine running around the
recommended 200 to 215 break-in
temp. If too much heat is contained,
the engine can actually run too hot.
Make sure that you monitor the
engine’s temp closely for the first
couple of tanks until you get the right
amount of cover for the cooling head. This will, of course, depend
on your current weather conditions. Adjusting the cover up and
down, exposing more or fewer cooling fins, is a convenient way to
regulate engine temps.
For owners that do not have access to a temperature probe, a drop
of water on the cooling head (around the glow plug area) should
slowly sizzle for approximately 6 to 8 seconds around 200 to 210
degrees. If the water sizzles for only a few seconds, then it is likely
that it is over 220 degrees, and needs to cool down. If the water
takes a long time or does not evaporate at all, then the engine is
too cool.
We do not recommend that you operate your engine below 35
degrees Fahrenheit. If you insist on running your vehicle below 35
degrees, be aware that nitro engines may be very difficult to start
and tune at extremely cold temperatures. Also, at temperatures
below freezing, nitro fuel can actually begin to gel up, and this can
be harmful to the engine.
Follow the remaining break-in procedures as outlined in this Owners
Manual. This, along with the steps listed above, will ensure a good
break-in for your new nitro engine, and provide many hours of
enjoyment.
THE TRX 2.5 RACING ENGINE
