![background image](http://html2.mh-extra.com/html/o-s-engine/max-91sx-hring-c-spec-ps-viper/max-91sx-hring-c-spec-ps-viper_owners-instruction-manual_4498964006.webp)
10
INSTALLING THE GLOWPLUG
Install the washer on the
glowplug and screw
carefully into cylinder-
head, making sure that it
is not cross-threaded
before tightening firmly.
Glow plug
Washer
INSTALLATION OF THE ENGINE
The under-surfaces of all O.S. engine beam
mounting lugs are precision machined flat and
exactyly parallel to the engine's horizontal axis. It is
essential that the engine mounts in the model are
also accurately made and aligned. If they are not,
they will cause stress and distortion within the engine
itself, probably resulting in loss of performance and
internal damage.
The recommended screws for securing the engine to
the engine mounts in the model are 4mm or 4-40
steel Allen type. It is also advisable to use lock
washers or LOCTITE to prevent nuts from loosening.
Front view
CORRECT
Side view
Top surfaces are in the same plane.
Re-align the surfaces as necessary
INCORRECT
Top surfaces are not
in the same plane.
Top surfaces are not in the
same plane.
Engine does not rest firmly.
Make sure that only the under-
surfaces of the engine’s mounting
lugs are in contact with the engine
mount.
11
ABOUT THE PUMP SYSTEM
Please understand the pump construction before
piping.
Pump functions in accordance with the engine
r.p.m. Rotating the engine by an electric starter
without connecting battery to a plug sucks fuel.
Prolenged this action may result in over priming.
Attempt to start the engine with over-priming may
result in bending a connecting rod and damaging
the engine.
NOTE:
Fuel is pumped from the tank and delivered to the
carburetor. Set the main needle a little rich at early
stage.
With this system the pump delivers the fuel at
constant pressure even at idling. Then,
unconsumed fuel is returned to the tank ria one-
way valve which avoids getting rich at around
idling.
If the main needle is set correctly, fuel return will
stop at around 60% throttle opening. Therefore, in
the high air flight that requires wider throttle
opening the engine runs under the effects of
muffler pressure, pump pressure and main needle.
During hovering that requires around half throttle
the engine runs under the effects of muffler
pressure, main needle, mixture control and retur
fuel volume.
Install A 5 at center and
N o . 8 a t s e c o n d p o s i t i o n .
Summary of Contents for MAX-91SX-HRING C Spec PS VIPER
Page 18: ......