MVVS MVVS 190CN4 User manual

Operating instructions
MVVS 190CN4
No: 3014
Version 1.0
Before using the engine, please read these instructions carefully.
Congratulations on choosing the gas engine MVVS 190CN4 - 4 cylinder 190cc.
MVVS 190cc has been designed and manufactured for propeller-powered radio-controlled
model planes. It is able to meet all of your expectations of an aerobatic racing engine.
Technical specifications
Bore 40 mm
Maximum power output
Silencer INT 58.02
+MVVS headers 3246
20,5 HP / 6700 RPM
Stroke 38 mm
Maximum torque
Silencer INT 58.02
+MVVS headers 3246
22 N/m / 5900 RPM
Weight of complete
engine without
ignition*
4590 g Fuel Unleaded 95-octane
fuel
Weight of ignition unit 270 g Lubrication Oil with petrol in
mixture 1:40
RPM range 1000 –9500 RPM
Propeller recommended 32x12 2 blades
30x13 3 blades
* Some manufacturers state the weight of incomplete engines. The value in the table above
stands for the weight of a complete engine, including the spark plug, carburetor, drive
washer and prop screws.
Important notice
This engine is very specific 4 cylinder with different characteristics from classical
2 cylinder engines.
a) Two ignitions:
The first ignition - its hall sensor for front cylinders (close to the propeller) must
be installed on the adapted milled pad labeled by one point (one dent-dot between
two threads for hall sensor bolts.)
The second ignition - its hall sensor for rear cylinders (close to the firewall)
must be installed on the adapted milled pad labeled by two points (two dent-dots
between two threads for hall sensor bolts.)
b) Ignition battery test function
Is strictly prohibited to do the ignition battery test function as you are used to from
other 1 and 2 cylinders MVVS engines. This battery test function could cause
spontaneous accidental start of the engine.

Safety precautions
1) Never use the engine for any manned vehicles or powered paragliding.
2) When operating model planes, always follow the rules and laws in effect in your
country.
3) The manufacturer declines all responsibility for all damages arising from the operation
of models and other appliances driven by MVVS 190CN4 - 190cc engine.
4) Use always only original MVVS spare parts.
5) Never tamper with the engine construction.
6) Before each flight check very carefully that all the propeller screws are tightened up
and in good condition. If you use a spinner, check that it is tightened up, too. When
mounting the spinner always follow the assembly instructions.
7) Periodically check that the engine is firmly fixed to the engine mounts. Never start a
loose engine!
8) Always use a balanced propeller! Always replace the propeller when damaged!
9) Make sure that no part of your body intersects the plane of the spinning propeller.
10) Always wear close-fitting, well-fastened clothes when starting or operating the running
engine. Never wear loosely hanging clothes (tie, scarf, etc.).
11) Never try to stop the engine by any part of your body.
12) Always stop the engine either by turning off the ignition switch or by completely
closing the carburetor throttle valve.
13) Before starting the engine always make sure that the model is safely fixed in place and
cannot start moving.
14) Fuel is combustible and therefore must be kept in an enclosed container at a safe
distance from the engine when it is running.
15) When preparing fuel carefully follow the manufacturer’s or dealer’s instructions.
16) Small objects must be kept at a safe distance from the engine when it is running. Never
throw any objects towards the spinning propeller.
17) Be careful in choosing the location where you wish to start the engine. Avoid dusty or
sandy areas.
18) Start the engine in well-ventilated areas only. Never start the engine indoors.
19) When starting the engine make sure that bystanders, especially children (!), are at a safe
distance of at least 15 m.
20) The engine power output makes it possible to fly big models. Mal-operation of such
models may cause serious damage. Start using the MVVS 190CN4 190cc in model
planes only after you have mastered operating smaller models.
Selecting a suitable propeller
It is usually the case that propellers of the same dimensions coming from different
manufacturers are not the same. Oftentimes not even propellers of the same dimensions
produced by a same manufacturer are not the same. The engine power is best utilized when
the propeller dynamics curve and engine power curve (revolutions/power output) intersect in
the area of the engine top power output. Unfortunately, no propeller manufacturer provides
this information. Engine power output is also a variable quality. It depends above all on the
silencer used and can considerably vary. The situation is further complicated by
environmental parameters (temperature and atmospheric pressure in particular): low
temperature and high pressure increase propellers’input requirements by 20% in comparison
with input at hot weather.
Suggested propeller dimensions: two-blade: 32x12
three blade: 30x13
These values are only approximate and may vary with the factors described in the previous
section, as well as with the type of the exhaust system used.
The MVVS 190CN4 is designed for the power maximum by 5400 –5900 RPM (according
the headers and exhausts used). If this maximum performance is needed, choose the suitable
propeller so, the engine reach these speed on the ground (in fact slightly lower; depends on
the unloading the propeller in air in accordance to reached speed while flying).
We do not recommend using propellers, which allow turning the engine on the ground more
as 9000 RpM.
Fuel
Always use unleaded 95-octane petrol mixed in the proportion 40 volume units of petrol to 1
unit of Mobil Racing 2T oil. If necessary, quality brand-name synthetic oil intended for
racing two-stroke engines can be used too.
For running the engine in, please use MVVS Racing 2T oil that comes with the engine. Mix
it in the proportion 30:1.
Never use inexpensive oil developed for garden appliances or synthetic oils intended for the
operation of methanol model engines. The manufacturer declines all responsibility for all
engine damages arising from the use of low-quality fuel.
Store fuel in containers designed for this purpose. Do not use mixed fuel older than 90 days.
Assembly
The engine is fastened to place by four holders built in the crankcase. The engine can be
mounted directly to the firewall or an assembly kit can be used (special accessories). Use
screws M6. If you decide to fasten the engine using flexible motor mounts, always choose
parts with enough solidity and strength. Make sure to secure the screws against loosening
and regularly check that they are tightened up and in good condition.
Since air is used to cool the engine, sufficient air circulation under the cowl must be ensured.
Never forget about hot air outlet –which must be 3-4x bigger than the intake one. Gas
engines heat up to higher degree than methanol ones!
Do not forget that the engine needs oxygen from the air to be able to operate. Therefore
ensure access of air to the engine intake as well. Caution: intake of warm air from beneath
the cowl may cut the engine power output.
Caution! When mounting the engine in the model use seals to protect all openings and
prevent the pollution of the engine’s inside with sawdust, residual abrasives etc. Make
sure that the inside of the fuselage is clean and that all parts are tighten in place and
cannot be sucked inside the engine.

Exhausts
Use only factory-made exhausts pipes designed for this type of engine. Preferably MVVS
exhaust system, which also guarantees the announced power output. The manufacturer
declines all responsibility for all engine damages arising from the use of improper exhaust
systems.
When mounting the exhaust follow the manufacturer’s instructions. Make sure to secure
sufficient cooling of the exhaust.
Carburetors adjustment
Both carburetors are adjusted before you buy it. It is not usually needed to change this
setting (always apply if used recommended exhaust system and propeller).
Caution! All settings make only if engine does not run. Injury may be caused by propeller.
Always set the same adjustments on both carburetors !
Basic setting: adjusting needles (L) for low revolutions range: 2 turns
adjusting needles (H) for high revolutions range 1,5 turn
(the values are derived from the position of clock-hands, starting position: fully closed
needle)
Caution! Never tighten the adjusting needles with too much strength. This may cause
damage of the needles. If the needles are damaged this way it is no longer possible to adjust
the carburetor and it is necessary to exchange it for a new one.
The new engine comes adjusted to the basic setting. This setting should be kept during the
running in!
After the engine has been run in, adjust it following the instructions below:
- start the engine and warm it up
- let the engine run at idle speed for approx. 5 seconds
If the engine starts to run backwards do not open the throttle - stop the engine
immediately! Otherwise the engine could be damaged!
Step I
- Accelerate to 2/3 of the throttle range within approx. 1 sec (faster acceleration). Repeat
three times –if the engine accelerates quickly and without a hiccup go to Step III. If
acceleration is not smooth go on to Step II.
Step II
- Faulty acceleration with hiccups and a tendency to cut out is usually attributable to a poor
fuel mixture in the medium-revolutions range. Stop the engine and recheck the fuel feed (the
hose-pipe must not be pinched or broken; if fitted, check also the fuel filter permeability).
Restart the engine and test acceleration again. If problems persist adjust both carburetors.
Open the adjusting needles L by 5 min and retest acceleration. If acceleration is smooth,
open the needles by another 3-5 min - this should be done because the needle was previously
set at a boundary value; if atmospheric conditions changed during flight, the problems might
recur.
- If the engine continues to malaccelerate open the needles by 10 min if the engine’s
operation does not improve, stop it and check the basic setting. Set the adjusting needles L at
2 turn and the adjusting needles H at 1,5 turn . Restart the engine and test acceleration. If the
engine runs correctly go to Step III. If it continues to malaccelerate, open the needles by
another 10 min. If it keeps malaccelerate, the defect is likely to lie elsewhere than in
incorrect adjustment. In such a case, go to the section on problem solving.
Step III
- If the engine accelerates correctly, according to the above test, set it at idle speed and
accelerate to full speed. Repeat twice more. If the engine functions correctly, go to Step IV.
If it cuts out, open the L needle by 5-10 min more.
- If the engine does not respond to acceleration fast enough keep closing the L needles until
the engine starts to cut out in response to gas. At that point reopen the L nozzle by 5-10 min.
Step IV
- If the engine reacts correctly set it at full speed. If revolutions do not drop, the engine has
been adjusted successfully. If revolutions seem to drop, open the adjusting needles H by
approx. 5-10 min.
Caution!!! Never close the choke valve completely when the engine is operating!
The choke valve is set to allow minimum air flow only when fully closed, which could cause
damage to the intake reed valve.

Starting and running a new engine in
Before you first start the engine, screw the plug in and tighten it up. Follow the instructions
on the box of the spark plug. Make sure that the plug socket is fitted in place and fastened
down properly; pull the wire ring over the hexagon.
Fix both ignitions sensors in proper positions above the magnet with screws enclosed.
Unless the spark plug is not inserted in plug socket, never turn the engine with ignition
turned on. This could lead to ignition damage!
1) Make sure that the ignitions are switched off, the choke valves are closed and the throttle
valves are about half opened. Then give the engine 3-4 turns, provided that carburetors are
not overflowing. If it is overflowing, give the engine 1-2 turns only.
2) Switch the both ignitions on, open the choke valves, set the throttle at slightly higher idle
speed and give the engine a few quickly turns. If even after the fourth turn, with the choke
valves opened, you do not hear a suggestion of the engine starting, give the engine 2 turns
following the instructions in paragraph 1 above. Then proceed according to instructions
given in paragraph 2.
3) If the engine does not start even after another set of turns open the throttle to maximum
and give the engine approx. 4 turns. Switch the ignitions off and on again and restart the
engine with throttle turned slightly down and the choke valves set open.
4) If the engine still would not start, unscrew the plug and check its contacts. Clean any
possible petrol moisture (i.e. an indication of engine overflow) and screw it in again. Further
starting should only be done with the throttle turned down. If the plugs are dry then probably
not enough fuel has been drawn into the carburetors. If that is the case, check the fuel feed
and then return to the instructions given in paragraph 1.
If the engine starts to run backwards do not open the throttle - stop the engine
immediately! Otherwise the engine could be damaged!
While the engine has been started, leave it run for approx. 5 min at a higher idle speed. Then
run it in for approx. 20 min, while changing revolutions from idle to 1/2-3/4 of the range and
shortly holding each position - gradually prolong the holding periods. After 10 minutes
running, start opening the throttle at maximum for short periods of time. Stop the engine and
let it cool down. Then restart it and check the adjustment. If everything is all right, you can
first take off. During first few flights do not overload the engine and do not let it run at high
revolutions for long periods of time (very important at hot weather). Use up all fuel that was
produced as a mixture with the oil that is included in the package. From now on, fuel and oil
should be mixed in the proportion 40:1.
·DO NOT PROCESS THE RUNNING-IN AT IDLE SPEED!
·A COLD ENGINE SHOUL BE WARMED UP BY SHORT
ACCELERATIONS (1-2 SEC)
Problem guide
The engine would not start:
–check the battery voltage; use the good brand battery only
–check and or replace the spark plug if needed (check the spark by inserting the
plug into the plug socket and turning the engine. The correct electrode spacing is
0,6 mm.)
–check the fuel supply
–turn the engine to check its mechanical condition
–check whether the carburetors needles are adjusted correctly
–take the carburetor off and visually examine the condition of the carbon-fiber reed
valve
–unscrew the carburetor cover on the side of the pressure inlet, check the fuel
screen possibly give the carburetor a blow with a current of air; when
reassembling, make sure you arrange the membrane and gasket in a correct order
–recheck the pressure hose attached to the carburetor
Replacing the reed valve:
–unscrew and remove the carburetor (mind the gasket)
–unscrew four M4 screws on the flange, remove the flange and take off the reed
valve (mind the gasket)
–unscrew four M2 screws and remove the old valves, replace them with new ones,
screw the screws back in and tighten them gently
–when reassembling, make sure you fix the gasket correctly
Mechanical faults of the engine must always be commit to a professional service
department!
Service information
After each 20 hours of running or 1 year change the spark plug.
After each 50 hours of operation time preventively check up the con-rod and the reed valve.
After 300 hours of operation time commit the engine to the professional warranty service
department.

Notes: Notes:

Warranty
The MVVS gas engines come with a three-year guarantee against defects in workmanship
and materials. Only original buyers of the engines are eligible warranty claimants. The
warranty cannot be transferred with a change in ownership.
This guarantee does not cover:
-any normal wear that might occur
-damage arising from accidents
-damage arising from the use of an unbalanced or damaged propeller
-damage arising from the use of a too small or a too big propeller
-damage arising from the use of low-quality fuel
-damage arising from the use of other than original spare parts and accessories
-damage arising from sucking a foreign object into the engine
-damage arising from any improper use
For further questions, please contact:
MVVS, spol. s r.o., tr. Kpt. Jarose 35, 602 00 Brno, Czech Republic
Tel. [phone], fax: [phone]
E –mail: mv[email protected]
Web: www.mvvs.cz
Certificate of Warranty
Date: Serial number: Dealer:
Buyer’s name and address: