CARBURETOR INSTALLATION
IMPORTANT
The carburetor on your engine comes preinstalled
from the factory; however, we suggest reading this section to
familiarize yourself with the steps to install the carburetor properly
should you need to remove it later for cleaning or maintenance.
❑
1) The carburetor is held in place using the pinch sleeve and
socket-head screw already
installed in the crankcase.
Slide the base of the carburetor
into the crankcase, being
careful to keep the carburetor
perpendicular to the front of
the engine. With your thumb,
push down on the carburetor
firmly so the base of the carburetor fits completely into the crankcase
and the carburetor o-ring seals the gap between the two parts. While
holding the carburetor in place, tighten the socket-head screw to
draw the pinch sleeve into place.
WARNING
Do not overtighten the socket-head screw. The screw
only needs to be tightened enough to keep the carburetor from
turning in the crankcase. Overtightening the socket-head screw
can cause severe damage to the base of the carburetor.
Please first familiarize yourself with the location of the idle stop
screw using the photo of the
carburetor on page 1. The
idle stop screw adjusts the
closure of the throttle barrel.
We recommend that the idle
stop screw be adjusted so that
the carburetor barrel stays
open about 1mm. Turning the
idle stop screw clockwise will cause the barrel to stay open more.
Turning the idle stop screw counterclockwise will allow the barrel to
close more.
FUEL RECOMMENDATION
Fuel can make a big difference in the way your engine performs.
For the break-in period you should use a fuel
specifically designed
for R/C car engines
that contains no more than 20% nitromethane
and 10%-14% oil content. Once the engine has been adequately
broken in (about 45 minutes of run-time) you can switch to a fuel
containing up to, but no more than, 30% nitromethane and 10%-14%
oil. We recommend using XTM Racing fuel.
WARNING
We do not recommend using fuels designed for R/C
airplane engine use. These fuels will cause the engine to overheat
and/or run erratically and severe damage to the engine will result.
GLOW PLUG RECOMMENDATION
The glow plug can make a big difference in how your engine
performs. We recommend using a "medium" or "hot" heat-range
glow plug intended specifically for performance engines like the XTM
Racing # 4 (P/N 146021) or the XTM Racing # 3 (P/N 146020)
during the break-in process. After the break-in period you may want
to use a different heat-range glow plug. Do not use glow plugs
intended for four-stroke airplane engines or glow plugs with an "idle
bar." Using the wrong type of glow plug will cause the engine to run
erratically and make it difficult to tune properly. The wrong type of
glow plug could also damage the engine.
The engine includes
an XTM Racing # 4 Medium heat-range glow plug.
WARNING ABOUT HYDRO-LOCKING
If at any time the pull-start becomes very tight or difficult to pull -
STOP!
The engine has become flooded and the excess fuel must
be removed or damage to the pull-start and/or engine could occur.
To remove the excess fuel from the engine follow the steps listed:
●
Completely close the high speed needle valve (turn it clockwise)
until it GENTLY bottoms out.
●
Remove the glow plug from the cylinder head.
●
With a rag over the top of the engine, pull the pull-start cord
several times to clear the excess fuel from the engine.
●
Check to make sure the glow plug has not been fouled, then
reinstall it. If the glow plug is fouled, replace it.
●
Reset the high speed needle valve 3.5 turns out from bottom
(turn it counter-clockwise).
HIGH & LOW SPEED NEEDLE VALVES
HIGH SPEED NEEDLE VALVE:
The high speed needle valve is used to meter the air/fuel mixture at
full throttle. Using a flat blade screwdriver, turn the needle clockwise
to lean the mixture or turn the needle counter-clockwise to richen
IDLE STOP SCREW
EXHAUST SYSTEM
Your new engine does not include an exhaust system. The exhaust
system is typically designed for the particular car, truck or buggy that
you have, thus is usually included in the model's kit. The engine
uses a standard 1/8th scale slip-on header (held in place with a spring
around the cylinder head).
IMPORTANT
For optimal power and performance, we suggest
using a 1/8 scale high-performance tuned pipe. The type of pipe
will depend on your particular vehicle and performance requirements.
2