VMAX VMX-42PRO Owner's Manual

2 STROKE ENGINE PROPELLER SIZES
(Diameter x Pitch in Inches)
ENGINE
SIZE BREAK
(cu in) IN AFTER BREAK IN
.049 5 x 3 5.25 x 4, 5.5 x 4, 6 x 3, 6 x 4 ,7 x 3
.09 7 x 3 7 x 4, 7 x 4.5, 7 x 5
.15 8 x 4 8 x 5, 8 x 6, 9 x 4
.19-.25 9 x 4 8 x 5, 8 x 6, 9 x 5, 9 x 6
.20-.30 9 x 5 9 x 6, 9 x 7, 9.5 x 6, 10 x 5
.35-.36 10 x 4 9 x 6, 9 x 7, 10 x 5, 11 x 4
.40 10 x 5 9 x 8, 10 x 6, 11 x 5
.45-.47 10 x 7 10 x 6, 11 x 5, 11 x 6, 11 x 7, 12 x 4
.50 11 x 6 10 x 8, 11 x 7, 12 x 4, 12 x 5
.60-.61 11 x 7 11 x 7.5, 11 x 7.75, 11 x 8, 12 x 6
.70 12 x 6 11 x 8, 12 x 8, 13 x 6, 14 x 4
.78-.80 13 x 6 12 x 8, 14 x 4, 14 x 5
.90-.91 14 x 6 13 x 8, 15 x 6, 16 x 5
1.08 16 x 5 15 x 8, 18 x 5
1.20 16 x 7 16 x 8, 16 x 10, 18 x 5, 18 x 6
1.50 18 x 7 18 x 8, 20 x 6
1.80 18 x 8 18 x 10, 20 x 6, 20 x 8, 22 x 6
2.00 20 x 8 18 x 10, 20 x 6, 20 x 10, 22 x 6
FUEL TANK SIZE
Recommended fuel tank size by engine displacement.
TANK
ENGINE
.10 cu in 60 cc (2 oz)
.19 120 cc (4 oz)
.25 120-180 cc (4-6 oz)
.29-.40 180-240 cc (6-8 oz)
.45-.50 240-300 cc (8-10 oz)
.60 360-420 cc (12-14 oz)
.76 420-480 cc (14-16 oz)
.90 480-600 cc (16-20 oz)
1.20 600-720 cc (20-24 oz)
Using too large a fuel tank can cause wide changes in
RPM as the fuel is consumed, wide changes in RPM
between inverted and upright flight, difficulties maintain-
ing a consistent fuel flow in vertical maneuvers etc.
Using too small a fuel tank will reduce flight times.
VMAX is a Trademark of VMAR Manufacturing Inc. and authorized VMAX agents worldwide.
Copyright Richmond RC Supply Ltd 2002. email: vmax@richmondrc.com
Please note that the best propeller size for your engine
may vary considerably with altitude, air temperature, air
humidity, fuel, nitro content and aircraft drag. Experi-
enced flyers and your local hobby retailer may have
suggestions for optimizing performance in your flying
area.
As a general guideline, lower pitch results in more
torque (vertical pull) while higher pitch results in more
speed in level flight.
A crude method of comparing one propeller to another
for level flight performance is to calculate the Power
Factor as (2 x Diameter) + Pitch. The bigger the power
factor the higher the performance the propeller... pro-
vided that the engine can handle the corresponding
load. For example an 11 x 7 prop has a power factor of
29 while a 10 x 6 prop has a power factor of 26.
If your engine appears to running overly hot and below
peak RPM you should try a propeller with a lower power
factor.
FUEL TANK POSITIONING
9mm (3/8")
As the distance between the vertical position of the
needle valve and the centre line of the tank increases
the following performance characteristics may be
noted...
- more fluctuation in RPM between inverted and upright
flight.
- more fluctuation in RPM between full tank and low
tank due to mixture changes
- more of a need for muffler pressure to smooth out
RPM fluctuations noted above.
- harder starting, more need for primer to start when
engine is upright
- more of a tendency for flooding, fuel siphoning from
tank into engine and hydraulic lock when engine is
inverted.
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8
Model engines, model engine fuel, propellers, spinners and products such as this VMAX model engine can be hazardous
if improperly installed or improperly used. Be cautious and follow all safety recommendations when using your VMAX
model engine and any third party accessories. Keep hands, tools, clothing and all foreign objects well clear of engines
when they are operating. Wear safety glasses when starting or operating this engine. Take particular care to safeguard
and protect your eyes and fingers and the eyes and fingers of other persons who may be nearby. Use only a good quality
Centre Line
propeller that has no cracks or flaws. Stay well clear of the propeller and stay clear of the plane of rotation defined by the
of Fuel Tank
propeller. Keep spectators and small children back at least 10 metres (33) feet at all times when operating the engine.
The manufacturer, distributor, retailer and/or other suppliers of this product expressly disclaim any warranties or represen-
tations, either expressed or implied, including but not limited to implied warranties of fitness for any purpose.
In no event will the manufacturer, distributor, retailer and/or other suppliers of this product have any obligation arising
from contract or tort, or for loss of revenue or profit, or for indirect, special, incidental, consequential or other damages
In purchasing and/or using this product, the user accepts all responsibility for its use and accepts all liability associated
Proceeding with Installation and/or Use of this product indicates
Agreement With and Acceptance of the Liability Disclaimer.
A model engine is not a toy. A model engine functions much like a full size engine. If you do not install and
operate this product properly you can cause injury to yourself and others and damage property.
You are solely responsible for the mechanical and operational integrity of this engine and the way in which it
is installed and used. Check all aspects of the installation, the engine, propeller, spinner and all other
accessories attached or associated with this engine before and after each use.
LIABILITY DISCLAIMER
It is important that the following liability disclaimer be
READ BEFORE INSTALLING OR USING THIS PRODUCT
arising from the use of this product.
with such use.
CAUTION
DO NOT INSTALL OR USE this engine if you are not qualified.
Do not operate the engine unless you are sure that it can be operated safely.
OWNERS
MANUAL