KAVAN FS400AR - Instruction manual

Introduction

Important: Before attempting to operate your engine, please read through this instruction manual to familiarize yourself with the controls and other features of the engine. Also, pay careful attention to the recommendations contained in the “Safety notes and warnings” chapter of this instruction manual.

Specifications

Displacement	12.8 cc x5 (0.781 cu. in. ×5)
Bore	26.5 mm (1 043 in.)
Stroke	23.2 mm ( 0.913 in.)
Power	5.55 kW/7,250 r.p.m.
Practical R.P.M	1,800-9,000 r.p.m.
Weight (w/Muffler)	2800 g. (6.17 Ibs.) incl. motor mount

Dimensions (mm)

	A	B	C	D	E	F	G	H
AP06A	24	10	45	M4	38.5	33
AP09A	30	11	58	M5	43.5	41
S15AII	31.5	11	62	M5	49.8	42.8
S32AII	38	15	74.9	1/4”–28	56.7	53.2
S36AII	38	15	74.9	1/4”–28	56.7	53.2
S40AII	44	17.5	84.3	1/4”–28	70.2	60.3
S46AII	44	17.5	85	1/4”–28	70	60
S52AII	44	17.5	85.8	1/4”–28	70.9	60.7
S61AII	52	25	97.8	5/16”–24	80.3	68.5
S91A	52	25	97.5	5/16”–24	84.7	67
108A	58	25	105.3	3/8”–24	90	73.7
180AR	68	36.5	133.7	3/8”–24	108	96.6
FS-30AR	36	14	64.7	1/4”–28	71	46.8
FS-52AR	44	17.5	80.6	1/4”–28	82.4	59.2
FS-70AR	50	21	89	5/16”–24	97.4	65.3
FS-80AR	50	21	90	5/16”–24	98.3	65.3
FS-91AR	52	25	90	5/16”–24	100	65.3
FS-120AR	58	25	106	5/16”–24	116.3	78.3
FS-180AR	58	25	111.8	3/8”–24	120	80.8
FT-160AR	80	68	120	5/16”–24	195.3	69.5	56.5	56.5
FS-400AR		Ø122	160.5	3/8”–24	Ø227	78

Safety Notes and Warnings

Important:

Remember that your engine is not a „toy“, but a highly efficient internal-combustion machine whose power is capable of harming you, or others, if it is misused.
Before attempting to operate your engine, please read through these instructions to familiarize yourself with the operations and features of this technical, fully operational model engine. Please read through the entire manual before operating this engine. Pay particular attention to the Safety Instructions and Warnings section of the manual.
Your new KAVAN engine will give you dependable performance and will be a source of satisfaction and pleasure if you follow these instructions as to the engine‘s proper and safe use. Do not let pleasure turn into injury and/ or tragedy! You alone are responsible for the safe operation of your engine, so act sensibly and with care at all times. This engine is a precision built machine whose power is capable of causing harm to you and others if abused, misused, or if you fail to observe proper safety precautions. As owner, you, alone, are responsible for the safe operation of your engine, so act with discretion and care at all times.

Always Remember:

1. Keep spectators, especially small children, who can be hurt when the engine is running at least 5-6 metres (20 feet) away from the operating engine. NOBODY should (including yourself) should be found in the plane of the rotating propeller!
2. Mount the engine securely in the plane, or on a proper engine test stand using high quality steel hex cap screws, washers and locknuts. Follow the mounting recommendations on the airplane‘s plan and/or instruction manual, or in the test stand described in the directions. DO NOT clamp this engine into a vice!
3. Use the correct size propeller and follow the recommended mounting procedures. Follow this instruction manual, the building plan/kit instruction manual; ask an experienced modeller or skilled model shop personnel if in doubts.
4. Install your propeller properly (looking from the cockpit of your model, the propeller of an engine installed in the nose rotates clockwise, looking from the front of the model it rotates counter clockwise). Use a proper wrench to tighten the propeller nut. Do NOT use pliers. Four stroke engines and large two stroke ones should use special safety locking propeller nuts.
5. Never touch, or allow any object to come into contact with, the rotating propeller and do not crouch over the engine when it is running.
6. Beware of the prop, protect your fingers. When hand cranking your engine, always us the „chicken stick“ (available in model hobby shops) or strong leather glove. Preferably, use an electric starter.
7. After starting the engine, carry out any needle-valve readjustments from a safe position behind the rotating propeller.
8. To stop your engine, adjust the throttle linkage so that the engine stops when the throttle stick and trim lever on the transmitter are fully retarded. Alternatively, the engine may be stopped by cutting off the fuel supply. Never try to stop the engine physically.
9. Discard any propeller which has become split, cracked, nicked or otherwise rendered unsafe. Never attempt to repair such a propeller: destroy it. Do not modify a propeller in any way. Also, check the tightness of all the screws and nuts regularly and frequently
10. If you have to carry the model to the take-off point with the engine running, be especially cautious. Keep the propeller pointed away from you and walk well clear of spectators.
11. Do not fly your model near or under power lines.

Safety Tips

1. The wearing of safety glasses is strongly recommended.
2. Do not start your engine in an area containing loose gravel or sand. The propeller may throw such material in your face and eyes and cause injury.
3. Take care that loose clothing (ties, shirt sleeves, scarves, etc.) do not come into contact with the propeller. Do not carry loose objects (such as pencils, screwdrivers, etc.) in a shirt pocket from where they could fall through the propeller arc.
4. Take care that the glow plug clip or battery leads do not come into contact with the propeller.
5. If you install a spinner, make sure that the slots for the propeller blades do not touch the blade roots and weaken them.

Warnings

1. Model engine fuel is poisonous. Do not allow it to come into contact with the eyes or mouth. Always store it in a clearly marked container and out of the reach of children.
2. Model engine fuel is also highly flammable. Keep it away from open flame, excessive heat, sources of sparks, or anything else which might ignite it. Do not smoke or allow anyone else to smoke, near to it.
3. Model engines generate considerable heat. Do not touch any part of your engine until it has cooled.
4. Never operate your engine in an enclosed space. Model engines, like automobile engines, exhaust deadly carbon-monoxide. Run your engine only in an open area.
5. Remember: Operating any model requires experience and constant attention to safety rules. Model airplanes, boats or cars have a lot of energy that can cause serious personal injury or significant property damage.

• Always proceed with caution!!
• If you are a beginner, ask for help and advice from an experienced modeller!
• Before trying to start the engine for the first time, carefully read the instructions and safety rules!

Features

The FS 400AR is a 5 cylinder radial overhead valve four-stroke engine of 4.00 cubic inch, 63.98 cc total displacement. The FS 400AR has been designed to meet the needs of the modellers who enjoy the larger airplanes, like 1/4 scale, who demand the high standards of refinements that are not available in larger displacement two-stroke engines.

FS 400 Accessories

• Radial Motor Mount
• 10 Leads for wiring Glow Plugs
• 5 Four-stroke Glow Plugs
• Display Stand
• Tool Kit
• Mounting Screws
• Needle Valve Extension Cable
• Choke Valve Rod
• Ground Wire 16 Gauge

Installation

The FS 400AR includes a strong one piece CNC machined aluminium radial type mount for easy and secure installation to the firewall of your aircraft. When installing the FS 400AR to the firewall of your aircraft, it is imperative that the firewall is strong, at least 15 mm thick and secure, and firmly attached to the structure of your aircraft.

Installation Procedures

• Locate the centre of the firewall.
• Place the engine on a sheet of paper, mount down. Using a sharp pencil, outline the outside radius of the motor mount.
• Then mark the exact location of the mounting holes.
• Take engine off sheet of paper, and find centre of outlined motor mount.
• Tape sheet of paper, matching centre of mount to centre of firewall.
• Drill mounting holes for 5 mm screws (M5 x 25) in proper locations.
• Secure the engine to the firewall, using the supplied screws, nuts and washers, making sure that the „KAVAN“ nameplate on the front housing is facing up.

Needle-valve extension

The needle-valve supplied with your FS 400AR is designed to use an extension so that the needle valve may be adjusted from outside the airplane once the engine is enclosed within the fuselage. A flexible cable with knob on 1 end, approximately 1.6 mm in diameter, should be inserted into the needle valve‘s centre hole. Secure cable by tightening the set screw in the needle valve with the small Hex key included with your engine. On the outside end of cable, secure the included know with the set screw using the small hex key.

Note: Do not use an excessively long extension cable that is unsupported, as this may cause a vibration which might affect the needle valve setting and/or damage the needle valve thread. If you need to have a longer extension cable so that the needle valve can be adjusted from outside of the airplane, always provide a suitable support at the outer end. Additionally, be sure not to position the support for the needle valve extension near the exhaust pipe.

Note: The carburettor cannot be reversed in order to reverse the needle valve location.

Choke Valve

• The choke valve operating lever can be located either on the left or right side by reversing the hexagon nut and cap screw.
• Unscrew the cap screw while holding the hexagon nut with the included wrench supplied, and refit the lever to your required location.
• If the supplied rod is too long, cut it to required length. An unnecessarily long rod may tend to vibrate. The rod should be as short as possible or should have its outer end supported.

Exhaust Pipe Adjustment

The direction of the exhaust pipes may be altered in accordance with individual installation requirements. The angle is easily adjusted by loosening the nut that secures the exhaust pipe to the cylinder head. Use the supplied wrench.

Carburettor Cleanliness

It is vitally important for all engines, including the FS 400, that the fuel entering the carburettor is pure and clean. For this reason, it is recommended that the fuel is passed through a filter when the tank is filled and that a good in-line filter is installed between the fuel tank and the carburettor.
Additionally, occasionally remove the needle valve holder from the carburettor and rinse out the locations shown in Figures 5 & 6 with methanol or fuel. Be careful not to lose the gasket when removing the needle valve holder from the carburettor.

Propeller Choice

The choice of propeller for your FS 400 depends on the size, weight, and performance level of the model. Determine the best propeller size after practical experiment. As a starting point, refer to the propeller chart below for expected RPM with specific propellers:

Propeller	RPM
18×10“	8 200–8 400
18×12“	7 200–7 400
18×14“	6 800–7 000
20×8“	7 900–7 200
20×10“	7 000–7 200
22×8“	6 900–7 100

Be sure to use only well balanced propellers only. An unbalanced propeller causes vibration and loss of power. It is also important to ensure that the propeller has no nicks, splits, or cracks and shows no other signs of wear.

Note: For safety reasons, at all times keep your face, hands, and rest of body well away from the path of the propeller during all operating procedures, including starting, and needle valve adjustments. Please refer to the Safety Instructions and Warnings in this Manual for added safety cautions.

Securing the Propeller to the FS 400AR

When securing the selected propeller to the FS 400, it is recommended to use the Propeller Safety Locknut Assembly, included with the engine, to prevent the propeller from flying off or splintering, even if it loosens. Be sure to securely tighten the propeller nut.
Installation of the propeller is as follows:

1. Ream the propeller centre hole 17/32 inch.
2. Balance the propeller.
3. Ensure that the Woodruff Key and drive washer are property and firmly attached. The Woodruff key allows the drive washer to lock into place, as it is the only place where the washer can slide into place to meet the crankshaft.
4. Fit the propeller nut and washer to the propeller, and screw onto the engine shaft. Tight nut firmly with wrench.
5. Insert the Propeller Safety Locknut Assembly and tighten firmly with wrench, being sure not to use excessive force.
6. It is important to remember, especially with wooden propellers, that there is a tendency for propeller materials to shrink due to wear or to heat. Always check to ensure that the propeller is properly secured to the shaft. Tighten the propeller nut if necessary after loosening the Propeller Safety Locknut. RE-Tighten Locknut once propeller nut is secure.

Glow Plug Heating

A 4 cycle engine fires every 2 revolutions, and it is imperative that a proper glow plug be fitted to the FS 400. Five 4 Cycle Glow Plugs are included with the FS 400AR. The original glow plug is recommended for best all around performance with this engine.

Note: If you choose glow plugs other than the original 4 Cycle, it is important to use the same type for all cylinders.

Glow Plug Ignition

For best performance, use an onboard battery to ignite the glow plugs when the throttle is set at half throttle or less. The onboard glow will ensure that all glow plugs stay „hot“ even when the engine RPM slows.

• The FS 400AR includes 10 (5 for spare use) spring loaded connectors for connecting the glow plugs to the battery. These special connecting heads will snap onto the head of the glow plug to ensure firm contact.
• Once the connectors are secure to the glow plugs, join the 5 glow plug leads together. If the connecting wires need to be extended once they have been joined, use an AWG16 or larger wire to employ a single lead.
• The glow plug wires should be connected to the positive battery terminal when in use.
• The Ground Wire can be connected to the motor mount, and will connect to the negative battery terminal.
• A 15 amps or larger capacity switch should be wired into the negative lead to turn the system on and off during transport and priming procedures. The switch should be easily accessible on the outside of the aircraft.
• A second 15 amps or larger switch should be wired into the same line as well and linked to the throttle servo to turn on when the throttle is set below + throttle. (Or you can use a suitable electronich glow heating device available in model hobby shops.)
• The battery source should be above 1.2 volts, and no more than 1.5 volts, and needs to have a capacity of 6-10 Ah. The use of a small lead acid battery or 4 -5 (wired in parallel) sub-C batteries has shown to work perfectly and should easily be carried by your aircraft.
• As an option, you may want to have a separate power source to use during starting procedures. The use of a separate battery will extend the time between charges of the on-board battery.
• Remember, if using an external battery, the onboard battery should be off. See Glow Plug Battery Section Below.

Glow Plug Battery

When starting the FS 400, it is necessary to use a glow plug battery of large capacity, 10 Ah or greater to heat 5 glow plugs simultaneously. A heavy duty 1.5 volt dry battery or preferably a 1.2 volt rechargeable NiCd battery may be used. A 2 volt lead acid cell (accumulator) may also be used but only if a method for reducing the voltage at the plugs is in place, since the plugs are only rated at 1.5 volt. See Below for instructions for 2 volt.

• If a lead acid 2 volt lead acid rechargeable cell is used, it is necessary to reduce the applied voltage at the glow plugs to approximately 1.5 volt. The recommended method is to insert an appropriate resistor in each individual plug lead. It is seriously discouraged to use a rheostat attached to the 2 volt cell, or to use extra long leads of at least 2 meters in length, to obtain the required drop in voltage. The disadvantage of this system is that if 1 glow plug should become disconnected, voltage to the remaining 4 glow plugs will be increased dramatically and may cause burning out of the elements.

Fuel

For consistent performance and long life of the engine, it is advisable to use good quality fuel containing not less than 18% lubricant, castor oil preferred, until a total of 1 - 2 hours of break-in has been achieved. Once break-in has occurred, the running characteristics of the FS 400 can be improved using a slightly lower lubricant content fuel, however, it may also shorten engine life. See Chart for Fuel Specifications:

Break-in
10-15%	Nitromethane
18%	Castor Oil
67-72%	Methanol

Lubrication

• AII parts of the FS 400 are automaticIy lubricated by the oil content of the fuel mixture.
• During the running of the engine, as well as while the engine is sitting properly mounted with the drain nipple pointed down, the excess oil will leave through the drain nipple. To protect your airplane, connect silicon tubing to the drain nipple and have it release the oil outside of your aircraft.
• After you complete your day of flight, run engine dry (removing fuel line from tank) to remove all methanol from the engine. The remaining castor oil in the engine will protect the engine. Be sure to use after run oil, SEE NEXT STEP!
• Make a habit of using after-run oil in your engine after each flying session. This will prevent rusting in the crankcase as well as preventing the excess castor oil from solidifying and locking the engine.

Operating the FS 400

Starting Precautions

• Note: For your safety and the safety of others, please observe the following instructions before attempting to start the FS400.
• Read and follow the „Safety Instructions and Warnings Section“ of these instructions.
• Make sure that an assistant helps you start the FS 400. Make sure your assistant, while securely aft of the aircraft, uses both hands and firmly holds the aircraft at the leading edge of the wing.
• Prime the engine properly. Turn the propeller counter clockwise to draw fuel from the fuel tank. BE SURE that the battery is not connected to the glow plugs.
• NEVER start the engine with the throttle fully open. Doing so will cause the aircraft to move forward abruptly due to the strong thrust of the propeller movement.
• Never make any adjustments, other than to the needle valve, while the engine is running.
• The engine should be started by rotating the propeller on counter clockwise, when viewed from the front.
• The engine may be hand-started; however, the use of a High Torque electric Starter is strongly suggested.
• After the engine has been run, residual oil will tend to accumulate in the lower 2 cylinders. This also happens in the full size radial engines. Between flying sessions, this accumulation may be great enough to prevent the pistons from passing over top dead centre on the compression stroke, i.e.: a hydraulic lock will occur. Any attempt to start the engine in this condition may cause serious damage. Make sure that this type of damage does not occur by first removing the glow plugs to allow the excess oil to drain out of the glow plug holes.
• Strongly recommended also is to disconnect the tubing from the fuel tank to the carburettor, especially if the fuel level in the tank is above the carburettor, as fuel can be siphoned into the engine if you do not disconnect the tubing.

Starting Procedure

1. From a completely closed position, open the needle valve 2 - 3 turns.
   • MAKE SURE THAT GLOW PLUG BATTERY IS NOT CONNECTED. THE GLOW PLUGS MUST NOT BE HEATED WHILE THE ENGINE IS BEING PRIMED.
2. Prime the engine by opening the throttle valve fully, and closing the choke valve while turning the propeller counter clockwise through 2 full revolutions.
   • If strong compression is felt when trying to rotate the propeller counter clockwise, too much fuel has been drawn into the engine. If this occurs, do not use force! Remove all glow plugs from the engine. Then, ensure that the choke valve is open and turn the propeller clockwise to force fuel out of the engine through the exhaust pipes.
   • Warning!!!! Never close the choke valve when applying the starter to the engine. Doing so will cause too great an amount of fuel to be drawn into the cylinders and will result in hydraulic lock and the risk of severe damage. See Fig. 20
   Note:After the engine has been primed, excess fuel may drip from the carburettor when the choke valve is reopened. Therefore, if your engine is enclosed in a cowl, be sure to fuel proof any surface that may be accessible to these fuel drippings to prevent fuel from penetrating the airframe structure.
3. Release the choke control and immediately turn the propeller counter clockwise several times so that fuel is drawn well into the cylinders.
4. From the fully closed position, set the throttle valve approximately half open. See Fig. 22.
5. Using an Electric Starter with your FS 400:
   • Be sure that the direction of the rotation of the starter is correct.
   • Connect the glow plug battery.
   • Apply the electric starter.
6. Hand starting your FS 400:
   • Note: Be sure to us a heavily padded glove or chicken stick when hand starting the engine.
   • Ensure that he propeller is fixed in such a way that it is positioned horizontally as compression is felt.
   • Connect the glow plug battery.
   • From the centre of the right blade, firmly swing the propeller counter clockwise.
7. Once the engine starts, open the throttle valve completely and allow it to run (approximately 10 seconds), with the original needle valve setting.
8. Make sure that all 5 cylinders are firing.
   • The engine is running properly if white smoke is emitting from all exhaust
   pipes equally. You will find a slight fuel spray from the exhaust pipe of any cylinder that is not firing.
   • If you are not using the onboard glow system and a cylinder stops firing,
   reduce the throttle setting to approximately half open from the fully closed position and re-connect the glow plug battery. You will notice the propeller revolutions will increase once all cylinders are firing consistently.
9. The firing order of the KAVAN FS 400AR 5 Cylinder engine is 1, 3, 5, 2, 4 as seen from behind the engine. See Figure 2

Adjusting the needle valve

• Abrupt adjustment of the needle valve may cause the engine to stop, especially when it is new and in not fully broken in.

Disconnect the glow plug battery.

• As the speed of the engine does not instantly change with the needle valve readjustment, small movements, with pauses between, are necessary to arrive at the optimum setting.

Re-starting the Engine When Warm

To re-start the engine when warm, simply re-energise the plugs, and re-apply the starter with the throttle in the idling position. If the engine does not start, disconnect the battery from the glow plugs and re-prime by closing the choke valve while rotating the propeller twice with the throttle open. Initially, the high temperature inside the combustion chambers may turn the liquid fuel into gas and emit it through the exhaust pipes. Therefore, repeat the priming procedure once or twice until the cylinders become cool enough for re-starting.

Break-in Procedure

AII internal combustion engines benefit, to some degree, from extra care when they are run for the first few times. This process is known as breaking- -in an engine. This is to allow the working parts of the engine time to settle down after being subjected to high temperatures and stress. However, because KAVAN FS engines are made with the aid of the finest modern precision machinery and from the best suitable materials, only a very short and simple break-in procedure is required and can be carried out with the engine installed in the model. We suggest using an 18 x 10 or 20 x 8 propeller for breaking-in.
Start the engine and run it for about 10 seconds with the needle valve set at half open, allowing engine to reach about 6,300 RPM, then open the needle valve to reduce speed to approximately 5,000 RPM and run for 20 seconds at this cooler setting. Keep the throttle fully open, using only the needle valve to reduce speed.
Repeat this procedure, alternately running the engine fast and slow with the needle valve adjustments, while gradually extending the short period of high speed running until the engine has been run at least 10 minutes. Once this minimum 10 minute ground break-in has been achieved, continue break-in in the air.
For the first few flights, set the needle valve as rich as possible, consistent with necessary take off power and, if necessary, readjust the throttle trim on the transmitter so that the engine does not shut off when the throttle is fully closed.
After every flight, close the needle valve slightly until, after at least 10 flights, set the needle valve for maximum power. The carburettor can now be adjusted for optimum throttle performance with the Throttle Valve Adjustments. See next section.

Throttle Valve Adjustment

The carburettor of the FS 400 has been set at the factory for best performance with the fuel tank located in the normal position (close to the back of the engine and where the level of the needle valve is at 2/3 height of the tank). However, the settings may, in some cases, vary slightly because of variations of fuel and climate. Additionally, during engine break-in, the needle valve is set rich, thus, the carburettor cannot be expected to show the best response. Therefore, it is recommended that the FS 400 be run first with the throttle settings as set at factory. After proper engine break-in, check the operation of the throttle according to the “IDLE ADJUSTMENT DIAGRAM” on the following page.

Note: Only adjust controls when necessary.

Adjusting the Idle Mixture Control Screw

The special carburettor fitted to the FS 400 controls the amount of fuel entering the engine according to the throttle opening and thus, maintains the correct mixture strength at all speeds from idle to full power. As previously explained, the idle mixture control screw is set at the factory, but should be rechecked after proper break-in:

1. Start the engine, allow it to warm up, and then close the throttle. Allow engine to idle for a few moments and then reopen the throttle for full power. If engine performs well, move to Flight Section. If engine hesitates, move to Step A, B, or C.

Note: Any adjustments to engine should be done after engine is shut off.

1. If the engine hesitates at this point, while emitting an amount of smoke before acceleration, the setting is too rich. If the setting is too rich, turn the Idle Mixture Control Screw clockwise to lessen the mixture. About 1/12 (30 degrees) turn should correct the mixture setting.
2. If the engine stops or is slow to pick up speed, without smoking, it is probable that the idling mixture is too lean. In this case, it will be necessary to turn the Mixture Control screw counter clockwise, approximately 1/ 12 (30 degrees) turn should correct the mixture setting.
3. If the revolutions increase but the engine still appears sluggish, it is possible that one of the cylinders has stopped firing. This can be detected by checking for exhaust from all pipes. The cease firing of the cylinder may be caused by the idling speed being set ton low or the idling mixture either being too rich or too lean.
• Normal safe idling speeds are in the 2,000-2,200 RPM range.
• If the idle speed is set too low, reset the idle at a higher RPM using the throttle trim on the transmitter.
• If the idle mixture is too rich, turn the Idle Mixture Control Screw clockwise
approximately 1/12 (30 degrees) turn should correct the mixture setting.
• If the idle mixture is too lean, turn the Idle Mixture Control Screw counterclockwise approximately 1/12 (30 degrees) turn to correct the mixture setting.

Note: Please note that a 5 cylinder, 4 cycle engine may appear to have a higher idling RPM than actual. It is strongly recommended to always use a tachometer when determining actual idling RPM.

Note: Readjustment of the carburettor may be necessary whenever a change of glow plug or fuel is made.

Resetting the Idle Mixture Control Screw

While carburettor adjustments are being made, it is possible that the Mixture Control Screw setting may be unintentionally changed. The pre-set setting can be found as following:

• Carefully tighten the Mixture Control Screw until it is completely closed.

Then turn the Screw a full 2 revolutions back.

Note: If an onboard glow plug system is being used with the FS 400, it is proper to have the system operating while adjusting Mixture at idling speed.

Flight

Engine Check before Flight:

• Ensure that all 5 cylinders are firing.
• As with a full size car or airplane engine, it is essential that the FS 400 is properly warmed before flight. Once started, allow the engine to run at full throttle for at least 10 seconds before releasing the model. NEVER attempt to takeoff immediately after the engine has been started.

Instructions for Valve Adjustment and Tool Kit

Valve clearances are correctly set before any KAVAN four stroke engine leaves the factory. In normal use, the valve clearances are not necessary to adjust until extended running time of the FS 400. However, in case of loss of power after extended running time or when the related parts are replaced due to crash, etc., valve clearances should be checked and adjusted.
Additionally, we suggest that after proper break-in of the FS 400 carefully check to ensure that the valve clearances are correctly set.

Note: ONLY check and re-set the valve clearances when the engine is cold.

Important: Valve clearances that are too small may cause difficulty in starting your FS 400AR because the valve will not be able to close properly, while valve clearances that are too great may cause loss of power because the valve will not be able to open sufficiently.

A: To check the valve clearances:

1. Remove rocker cover by unscrewing the hex cap screws from the rocker box on the top of the cylinder head. Use the hex key supplied with your FS 400AR to remove the hex cap screws.
2. Turn propeller until compression is first felt. Once you feel compression, turn the propeller an additional 1/4 turn. At this position, both valves should now be closed.
3. With the valves closed, the required valve clearance is between 0.04 mm and 0.10 mm (0.0015 to 0.004 inch) measured between the valve stem and the rocker arm. Use the 0.04 mm and 0.10 mm feeler gauges to check clearances. (See Fig. 29) If tolerances are within range, move to step 4. If tolerances are outside of range, see NOTE and move to step B.
4. It is important to ensure that the valve clearances are consistently within range. It is for this reason that all valve clearance checks are completed. Rotate propeller through compression stroke (approximately 2 rotations) and complete steps 2 & 3 again to ensure that tolerances are within range. Complete step 4 again.

Note: In most cases, the 0.04 mm feeler gauge should pass through the gap, while the 0.10 mm feeler gauge should not. However, if your engine is starting easily, and running satisfactorily, it may not need any adjustment, even if the valve clearance is below 0.04 mm, and up to 0.14 mm (can be tested by having 0.04 mm and 0.10 mm on top of one another).

B: Setting Valve Clearances

If your engine is not starting easily and running satisfactorily and the gap is found to be less than .04 mm, or greater than .10 mm, reset the valve clearance as follows:

1. Using the special offset wrench included with your FS 400, carefully loosen the locknut on the rocker arm about 1/4 to 1/2 turn. See Figure 30.
2. Using either the supplied screwdriver, turn the adjusting screw approximately 1/2 turn counter-clockwise to open gap with matched tool at screw head. See Figure 31.
3. Insert the 0.04 mm feeler gauge between the valve stem and the rocker arm. Using your fingers, turn the adjusting screw clockwise until it stops. See Figure 32.
4. While the 0.04 mm feeler gauge is still in place, use the screwdriver at screw head to hold adjusting screw in place, and tighten the locknut with special offset wrench. See Figure 33.
5. Remove the 0.04 mm feeler gauge and re-check valve clearance by completing Steps A: 1 - 3. If the valve clearance is correctly adjusted, check fit, and secure rocker cover in place.

Care & Maintenance

To ensure that you obtain long life and peak performance from your engine, observe the following.

• Avoid running the engine under dusty conditions. If necessary, lay a sheet of plywood under and around the nose of the model when starting the FS 400.
• Clean fuel is essential to keeping the carburettor clear and the engine running properly. To ensure clean fuel, following these steps:
• Rinse the fuel tank with methanol before installing in aircraft.
• Install a fuel filter between tank and carburettor.
• Install a fuel filter between fuel pump and tank.
• Check and clean filters often.
• Keep fuel can closed whenever not in use.
• Do not close the needle valve to too lean a setting. This lean setting will cause overheating and slowdown the engine performance.
• Additionally, this setting will cause internal rusting of the engine due to nitromethane oxide being produced by the high engine temperature. Always adjust the needle valve very slightly to the rich side of the peak RPM setting.
• After every use, always clean the exterior of the engine with a clean cotton cloth. This will prevent oil and dirt from burning, and blackening the exterior of the FS 400.
• If the FS 400 is not to be run for more than 2 months at any time, remove the glow plugs and rinse out the interior of the engine by injecting kerosene (not gasoline) into the cylinders through the glow plug holes and into the crankcase through the drain nipple. Once the kerosene is injected, slowly rotate the crankshaft to and fro, distributing the kerosene and dissolve residue throughout the engine. Once this has been accomplished, drain out the kerosene mixture by turning propeller to help remove it from cylinders. Finally, add light machine oil through glow plug holes and drain nipple, rotating crankshaft slowly to distribute oil to all working parts.

What to Do in the Event of a Failure?

A guide to the warranty and post-warranty repairs

Warranty Conditions

Since this engine, which requires regular maintenance and care, is intended for operation by the modeller under conditions of much higher performance and load on the model than those to which toys in the ordinary sense of the word are exposed, we cannot assume (and it cannot be supposed) any guarantee relating to how long it takes before individual parts need to be replaced due to wear. Engine parts wear out and require replacement over time. If any part of the engine appears to be damaged, defective or incorrectly installed when the engine is new – before the first start – this part will be repaired or replaced free of charge. Engines are only protected by the warranty against manufacturing defects in material, workmanship or assembly when new (before use).
If any part is found to be defective, incorrectly manufactured or incorrectly assembled during the statutory warranty period, it will be repaired or replaced by the importer free of charge. If you believe that the defect in material, workmanship or assembly was not apparent when the model was new and only became apparent after the product was used, then please contact KAVAN Europe s.r.o. (e-mail: info@kavanrc.com, tel. +420 446 260 133). We firmly believe in the quality of the products we sell and will do our utmost to ensure that you are satisfied with them.

Warranty Limitations

This warranty does not cover damage caused by improper or rough handling, negligence, accidents, water or excessive humidity, damage caused by chemicals, improper or negligent maintenance, neglect of maintenance, accidents and acts of God, unauthorized changes or modifications, use of incorrect fuel. The warranty does not cover engine parts that are considered consumables (spark plugs, oils, etc.). KAVAN Europe s.r.o. does not cover the costs of transporting defective parts from the user.

Role of the Model Shop

The shop where you have purchased the engine is the first place where you should apply for a warranty repair or complaint. The dealer can help with identifying a possible defect and communicating with the importer. Only if for some reason it is not possible to use the services of the shop where the model has been purchased, contact KAVAN Europe s.r.o. directly.

Limitation of Liability

KAVAN Europe s.r.o. does not provide - nor can it be assumed to provide - any other warranties. KAVAN Europe s.r.o. is not responsible for any special, incidental or consequential damages arising from the assembly or use of its products, accessories or chemicals required for the use of its products. The moment the product is used or operated, the user assumes all liability arising therefrom. In no event shall KAVAN Europe s.r.o.‘s liability exceed the actual sales price paid for the product.

How to send products for warranty or non-warranty service?

First, email or call the importer or service centre. It often happens that a product may appear defective or malfunctioning simply because it has not been used correctly or requires only simple adjustment. One email or phone call to our experienced service technicians can solve everything quickly and easily! When sending your product for service check/repair, please remember to include:

• A copy of your proof of purchase
• A return address
• A telephone number where you can be reached during business hours
• Your email address
• A detailed description of the problem

Preparing Your Motor for Service

• The guidelines below will help you save on postage and assist our service technicians in carrying out repairs and returning products.
• Clean the engine before shipping to avoid paying an additional cleaning fee.
• Do not send fuel, batteries, accumulators, chargers, glow plug clips and glow plug heating devices, operating instructions or other accessories that you use when operating your engine (unless the service technician requests that you send one of these items). You will save on postage and avoid the risk of loss during transportation. KAVAN Europe s.r.o. is not responsible for the loss of unwanted accessories during transportation to the service or repair.
• When sending the product to the service, insure the product for the price corresponding to the newly purchased product. KAVAN Europe s.r.o. is in no way responsible for the loss of the product during transportation to the service.
• Pack the product thoroughly and securely in a hard cardboard box of appropriate dimensions. A freely moving engine in a large box can only cause additional damage.
• If possible, avoid using shredded paper or foam padding. If this cannot be avoided, place the padding or motor in a sealed plastic bag(s).
• Include all documentation needed to repair the motor, along with as detailed and concise a description of the fault or problem as possible.
• Include a telephone number where you can be reached during the business day and an email address so that the service technician can contact you with additional questions about the repair.
• Include a note with your address. It is surprising how often this is forgotten.