Soviet industry left behind a rich legacy, and in the segment of small craft one of the brightest representatives was the legendary shipyard. ArrowThis one. outboard It has long been a symbol of accessibility and simplicity, allowing thousands of fishermen and tourists to scour the waters without much technical difficulty. Despite its venerable age, interest in this model is not fading, and enthusiasts continue to look for ways to revive and upgrade old units.
Why is this particular engine so exciting decades after mass production ceased? The secret is its amazing maintainability and modular design, which allows it to restore even badly worn out units to work. boat-arrow for its unpretentiousness to the quality of fuel and the possibility of carrying out repair In the field with a minimum set of tools.
In this article, we will discuss in detail the technical device of the unit, consider typical malfunctions and compile a step-by-step algorithm of actions at start-up. You will learn how to properly configure the carburetor, where to look for hidden defects of the lower unit and what nuances of operation are often ignored by beginners. A critical point is to comply with the proportions of the mixture of oil and gasoline, since working on pure gasoline will instantly disable the piston group.
Historical background and technical specifications
Development Arrows The Soviet machine-building industry was designed to produce a mass-produced, cheap and reliable engine for the population, and the designers relied on a two-stroke cycle and air cooling, which made the design much easier than water-powered ones. A 4 horsepower engine seemed to be enough for the lightweights. PVC boats Small metal boats of that time.
The technical parameters of the unit look modest by modern standards, but they fully corresponded to the requirements of the era. The engine developed about 2,500 revolutions per minute, providing a speed of travel by boat up to 12-14 kilometers per hour. capacitor and candles.
It is worth noting that there were different modifications, different year of production and manufacturer, some versions were equipped with more advanced carburetors, others had a reinforced lower unit pipe.
| Parameter | Meaning |
|---|---|
| Type of engine | Two-stroke, petrol. |
| Workload | 94 cubic centimetres |
| Maximum power | 4 hp (at 4000-4500 rpm) |
| Ignition system | Contact (magneto) |
| Weight (no fuel) | About 13-14 kg |
Design features and device
Component boat-engine Arrow The engine is made up of three main components: the power unit, the lower unit and the suspension, and the power unit is enclosed in a lightweight aluminum casing that simultaneously acts as a shield and guide for the flow of cooling air. The crank-shaking mechanism It is very simple here, but requires regular lubrication.
The torque transmission system deserves special attention. Unlike modern models, it used a friction clutch that automatically turned on when the engine was turned up, which allowed the engine to start idling without rotating the screw, but over time friction linings wore out, requiring replacement or adjustment of gaps.
⚠️ Attention: The clutch design is not designed to work in water at low speeds for a long time, as this can lead to slipping and overheating of the friction nodes.
A lower unit pipe connects the engine to a propeller, and it's got a shaft inside it, and in some versions, it's got a reverse thrust, although it's classic. Arrow Often it did not have a full rear gear, requiring the entire engine to rotate backwards, the propeller was made of aluminum alloy and had a fixed pitch, which limited the ability to adjust for different loads.
The secret of bearing durability
Many owners are unaware that lower unit uses bearings that require periodic lubrication through special oils or by stuffing with a consistent lubricant during disassembly, ignoring this leads to a jamming of the shaft.
Power and ignition system
The heart of the fuel system is a float carburetor, which prepares a combustible mixture that then enters the crank chamber, and the main problem is often the loss of sealing of gaskets and glands, which leads to air sucking and depletion of the mixture. jelly and the fuel level in the float chamber.
The ignition system is based on a magdino under the flywheel. The generator generates a low voltage current that is converted to high voltage discharge by the coil. The key element of reliability is a capacitor that dampens the spark in the interrupter contacts. If the contacts burn too fast, the first thing to check is the capacitor that extinguishes the spark in the interrupter contacts. capacitor.
- 🔧 Adjustment of the gap between the contacts of the interrupter shall be made with an accuracy of 0.25-0.35 mm.
- ⚡ The angle of ignition advance is exposed at risk on the flywheel and requires a special tool or strobe.
- 🕯️ The spark plug must have a kalyl number corresponding to the thermal regime of the engine, usually A11 or A17.
Incorrectly adjusting the advance can lead to detonation or overheating of the piston. Owners often face a situation when the engine stalls under load - this is a sure sign of a violation of the piston. forward or contamination of contacts.
To protect the contacts of the interrupter from oxidation, use a special lubricant for high-voltage systems or regularly wipe them with suede soaked in gasoline.
Typical malfunctions and diagnostic methods
The use of age-related equipment is inevitably fraught with breakdowns. strarrow This can be caused by wear on piston rings, cylinder swelling, or the breakdown of the crankshaft coils, and the diagnosis begins with visual inspection and listening to the engine for foreign knocks.
The second most common cause of failure is the fuel supply system, clogging of channels, oxidation of membranes or leakage of the fuel hose causes the engine to stall or not start at all, and overheating due to contamination of the cooling ribs or imbalances in proportions is also common. fuel-mix.
☑️ Diagnostics before launch
⚠️ Attention: If there is a metal knock in the engine, immediately turn off the engine. Continued work can lead to the collapse of the rod and punching the crankcase.
For accurate diagnosis, it is recommended to use a compressometer. The normal indicator for this class of engines is the pressure in the range of 8-10 atmospheres. If the indicator is lower, you should disassemble the cylinder-piston group and defect parts. bearing the bottom head of the rod.
Launch procedure and operating rules
Launch boat-engine It requires a certain sequence of actions: first, you need to make sure that the motor is securely attached to the transom and the screw is submerged in water, then the fuel crane opens, and several pumping pears are made (if any) to fill the carburetor.
The lever is moved to the "Start" position, and the ignition is activated. With a sharp jerk of the starter cord, you need to turn the crankshaft. If the engine does not catch the first time, you should not immediately turn it for a long time - you should check it. candle for the presence of a spark and the state of the mixture.
Sequence of action:1. Hold the motor on the transom.
2. Put the lower unit in the water.
3. Open the fuel faucet.
4. Pull the trigger of gas (start position).
5. Start ignition.
6. Pull the starter cord sharply.
After starting, you need to let the engine warm up at low speeds for 2-3 minutes. Only then you can smoothly add gas and start driving. piston-group.
The main rule of longevity Arrows is high-quality running after any repair and the use of fresh fuel mixture with the right ratio of oil.
Maintenance and storage
Regular maintenance is the key to a long life for you. unitAfter each release, especially if salt water or a body of water with abundant vegetation was used, the motor should be washed with fresh water, which will prevent corrosion of aluminum parts and lower unit pipe.
Periodically, you need to lubricate the bearings and check the tightening of the fasteners, which tend to weaken from vibration. Pay special attention to the condition of the lower unit: the absence of cracks and dents is critical for safety. In the winter, the motor is preserved by draining fuel and treating the internal cavities. preservative.
- 🛢️ Change the fuel hoses once every 3-4 seasons, even if they look whole, as the rubber loses elasticity.
- 🧹 Clean the air filter (carburetor grid) of dust and down before each season.
- 🔩 Check the tightening of the nuts of the lower unit attachment to the suspension to avoid backlashes.
Store Arrow If this is not possible, make sure that the water is completely drained from the lower unit so that when it freezes, it does not break the metal walls.
Frequently Asked Questions (FAQ)
What is the ratio of gasoline and oil needed for the Arrow?
For the running of a new or repaired engine, a mixture of 1:25 (40 ml of oil per 1 liter of gasoline) is recommended. For continuous use, a ratio of 1:30 or 1:35 is used, depending on the quality of the oil and load.
Why does the engine of the Arrow stop at high speeds?
The most likely cause is impoverishment of the mixture due to clogging of the main jelly carburetor or air sucking through the glands, and it is also worth checking the angle of ignition and the state of the interrupter contacts.
Can I install an electronic ignition on the Arrow?
Yes, there are electronic ignition (non-contact) kits adapted for use on older Soviet engines, which greatly simplifies start-up and improves stability, eliminating the need to adjust the contact gap.
Where to find spare parts for the outboard motor Arrow?
Original parts are almost never produced, and can be found at car disassemblies, flea markets, specialized retro parts stores, or ordered from private craftsmen (pistons, gaskets, oils).