Congratulations on your purchase of an MDS engine. MDS engines are
noted for their excellent power, robust character, and efficient operation.
All MDS engines are designed to precise tolerances and should be handled
with care. The following information and recommendations are presented
to help you become more familiar with the assembly and operating
characteristics of your new MDS engine. For best results, please closely
follow the break-in procedures and adjustment suggestions. Also, be sure
to read the enclosed safety instructions and warranty information prior
to operation.
A. Assembly
Inside the MDS engine box you should find one each of the
following items as shown in Photo 1:
To assemble your new engine, please follow these simple steps:
1. Remove the individual plastic bags from the box and place
them on a table or workbench in front of you. Remove the
engine from its plastic wrapper. Note: Some engines may
already have the carburetor installed. If so, it will be neces-
sary to remove the carburetor at this time. If the carburetor
assembly does not remove easily, it may be necessary to
loosen the carburetor retaining bolt slightly (see Photo 2)
using the Allen wrench supplied in the parts/tool bag. Next,
rotate the carburetor back and forth slightly while pulling
upward to remove the carburetor.
2. Remove the two O-rings from the parts bag. Install the first
O-ring into the cavity of the air intake port of the crankcase,
as shown in Photo 2, making sure that the O-ring is seated
evenly at the bottom of the cavity and cannot come in
contact with the engine crankshaft. The second O-ring is a
spare.
3. It is now time to re-attach the carburetor to the engine.
Before inserting the carburetor, inspect the carburetor retainer
to insure that the curved portion of the carburetor retainer
drawbar matches the inside wall of the air intake port. If it
does not, simply place it in position with your finger. Before
tightening the carburetor to the engine, it’s suggested that a
downward pressure be applied to the carburetor to create an
airtight seal to the O-ring. Align the carburetor so the needle
valve is 180 degrees to the crankshaft of the engine and
secure if using the provided Allen wrench.
Note: The carburetor is correctly positioned when the
throttle arm is located on the right side of the engine when
viewed from the rear.
CAUTION: Do not overtighten; doing so could damage the
carburetor body.
4. Move the carburetor barrel to its full idle position and adjust
the barrel stop screw so the air passage of the carburetor bar-
rel is completely closed as shown in Photo 3 on the next
page. This will allow for the engine to be shut off by moving
the throttle trim of your transmitter to the full low position
during operation. Note: It’s important to do this procedure
at this time as the barrel stop screw is not accessible once the
engine is installed in the helicopter.
A. Engine assembly
B. Aeromix
™
carburetor
(may be pre-installed)
C. Complete accessory and
tool set (included tools
may vary slightly with
different engines)
D. Two muffler mounting
bolts (.38 & .48 only)
E . Tapered collet and
knurled prop washer
(.38 & .48 only)
F. Extended heli throttle arm
(.38 & .48 only)
G. Two carburetor O-Rings
• Instructions and
warranty card
Pro Heli Engine Operating Instructions
™
Photo 1
Photo 2
A
Carb
Retaining
Bolt
O-Ring
B
C
D
(.38 & .48 only)
E
(.38 & .48 only)
F
(.38 & .48 only)
G
Version 1.1
