35 hours with Mercury 40 motor

40-horsepower two-stroke Mercury engine has been selected for the next long-term tests on its "measured mile". Fresh model «40ELPTO (2)" had all the modern systems: oil injection, hydrorakes, electric starting, fuel recycling, etc. We stopped on the power of 40 hp for two reasons: the first one is mentioned in the editorial introduction to the number, and the second - is dictated by the permissible capacity on the motor boats - a "Delta-T", which was tested at the same time (see KiY number 184.). Two-stroke rather than a four-stroke model was chosen for reasons of greater affordability and  familiar to ordinary powerboating driver, and most importantly - lower weight, which is important for easy installation on motor boats. Not the last argument was the ability to refuel with AI-92 fuel.

Impeccable reputation of the firm promised a trouble-free operation and a pleasant chat with this elegant handsome. Looking ahead, say at once that the first 35 hours we spent together, we did not disappoint and confirmed the highest opinion of the product with the brand «Mercury». However, it revealed some of the nuances that are sometimes put us into a dead end, forcing seriously delve into the device completely new modern engine *.

* It is not recommended to go into the new unit, located on the engine warranty. With emerging issues owners motors "the Mercury" can handle both the company "Mercury - NIITM" site www.mercuryonline.ru, and receive consultations of experts of the company, request literature.

The first key

«Mercury Marine» - one of the few engine-building companies, which allows the use of petrol with a relatively low octane number, specifying it this way: "not less than 90". Therefore, our AI-92 (by the way, in the West completely unknown) officially used during the test could, however, we decided to first, at least until the end of the full break-in, still use 95 octane.

In the first tank, as indicated instruction is not filled in clean gasoline and fuel mixture 1:50 with the addition of "merkurevskogo" oils such as «TC-W3». In conjunction with the existing system, the first hours of operation at the engine break-in oil injection were supposed to take place on the actual mixture ratio of 1:25.

They make all the necessary arrangements, and here it is - an exciting moment: the key "to start"! Revived starter broke laterally control the jet of water from the pump, however, the engine is silent. Repeat run five times in seven to nine seconds, with short breaks. Again nothing. Only now he is gone smoke. For the first run this is not surprising. After waiting five to seven minutes, repeat the run. Now the engine immediately "caught" and even earned. Striking quiet and smallish exhaust sound.

Translate idling gas lever to the minimum speed that the engine continues to hold steady. It lasts for a few minutes while we shovel with shallow water to deep water. Unexpected turn begin to fall. To prevent the motor stall, translate idling gas lever in the center position, but now the momentum start randomly "float". Visible explanation until we find.

Because of this, three times we fail to start when fully recessed lever idling and turn the knob to control the working progress of the neutral front, the motor immediately
the stalls. Just as much as possible to speed up all these manipulations, could gently turn forward drive and begin moving.

Motor gaining momentum exactly, without failure, no observations at higher revs his work does not matter.

Do not believe your eyes

In the early hours of the test we have avoided to give maximum speed and chose partial - intermediate - regimes, replacing them every one and a half to two minutes.

At a minimum sustained planing at speeds of 25-27 km / h regular readings tachometer close to 4500 rev / min - the border, which is not recommended more than when they were run. In this situation, regular screw with a pitch of 15 "was obviously legkovat. Replace it with a screw on the first step 16, "and then 17". Screws with a big step for these engines had to be specially ordered.

Indications staffing tachometer continue to surprise - at a set speed exceeding 40 km / h hand it is over a 6000 rev / min. This is - an obvious absurdity that requires quick resolution, because the walk at the speed higher than the nominal 5500, is strictly prohibited.

We get the second, «Stihl» company electronic tachometer. Fix the clamps on its high-voltage wire of the first cylinder candle and compare the performance of this device with the standard in all modes. They are very different: «Stihl» indicates that the maximum speed with a screw 17 "up 5100 rev / min, which seems to be true.

And then we dawns look under the dashboard on the end of the regular tachometer. It turns out that it has multiple measurement modes (e.g., 3P, 4P, 5P, 6P), each of which corresponds to a particular motor type. Switch to the desired mode, we have ensured that the testimony of "bounced back" staff unit, although the upper limit of the measuring small differences still remained. So firm and recommends that responsible operations (for example, the precise selection of the propeller) is still on the staff the unit is not relied upon.

Our mistake was that when installing the motor it all had to be determined.

Small gas - a big problem

Continuing to go to the break-in mode, while reducing speed to slow speed again we are faced with an unstable operation of the engine at idle. The first two or three minutes, the engine purred smoothly, then began failures, the motor more shaking, thick smoke appeared, and, if the driver did not intervene, stalling the motor. However, the cost of gas added, «Merc», sluggish and speeding rising rapidly gaining momentum and continue working as if nothing had happened.

The first revision undergone candles. They were covered with thick black soot, especially - the candle of the upper cylinder. After the candles were soak in a solvent, cleaned and checked for serviceability, this phenomenon disappeared for a short time, then the same thing happened again.

This happens on our own, "Vortex" at a working ignition system, we would do the carburetor. It is known, if the engine is at the minimum position of the throttle
stalls, so the quality of the idling mixture is too poor or insufficient amount of it. Idle speed control systems achieve stable operation, and if it is broken then it says nothing of the clogged jet of idling or change the fuel level in the float chamber.

Covered with soot as black candles, smoky exhaust and sluggish transition from mode to mode say too rich mixture, a large amount of oil.

As you can see, this is - are mutually exclusive phenomena. Moreover, it is not clear what happened in our case, when engine at short stops normal plant after pumping fuel and the first time sustainably kept idling at full lever is lowered gas idling.

All Western engines off the assembly line with a fully configured system, including a tuned carburetors. Stamp with the word "OK" and the personal number "testermena" -nastroyschika available on the cover of the exhaust manifold, ensures cleaner impersonal stamp our OTC or even military acceptance mark. So get into the carburetor of a new imported motor makes no sense, and it is necessary to look for the cause on the way from the manufacturer to the buyer.



The scheme and the service of fuel recycling system.
1 - non-return valve in the bottom cover casing;
2 - non-return valves at the inlet;
3 - carburetor connector;
4 - socket connector upper crankcase cover;
5 - tee.

Our motor is entered for the installation directly in the package, avoiding pre-training. At the factory each motor takes a short run-in, and then in the carburetor diffuser injected engine running special preservative composition, while the engine is not "suffocate". In this state, the motor without the risk of corrosion may be stored for up to three years.

Probably, our engine simply was not reopened its. Un-cleaned the remains of preservative seems to have accumulated in the recycling system and prevent proper operation. On this guess we imposed a white cloud suspended in the water, which periodically burst from the propeller hub at faults in engine work. Now this conjecture had to check.

Not a drop back!

Fuel supply system on two-stroke carbureted engines do not provide full delivery of fuel through the crankcase to the combustion chamber. Unburned fuel residues accumulate especially intensely at low revs. This not only harms the environment but also improves fuel consumption, increases the carbon formation, and so on. D.

All multi-cylinder models «Mercury» equipped with fuel recirculation system that starts to work in two or three minutes after the engine is started. This system is designed to collect unburned fuel and oil residues from the lowest point of each housing and return them back to the inlet nozzle through which fresh fuel is supplied.

Many recycling systems also collect fuel and oil is collected in the lower region of the crankshaft bearings, and re-injected them in the upper part, to provide the necessary lubrication of the bearings. It is clear that if the recycling system will not work well, it threatens a serious accident.

The efficiency of the engine also will decrease, especially at idle.

If you increase the speed, remaining fuel oil, and quickly get into the engine and over-enrich the fuel mixture.

Symptoms malfunction recirculation following:
- Low efficiency of operation at low speed;
- Poor acceleration of the motor;
- Lubrication of spark plugs;
- Engine stalls at idle speed;
- Excessive smoke during acceleration.

As you can see, they are fully consistent with our case.

Two-cylinder 40-strong «Mercury» models have internal and external recirculation system.

The first external system using non-return valves installed at the bottom of the crankcase cover. This system lubricates the upper bearing of the crankshaft.



oil injection system with the fuel mixture composition variables.
1 - the oil tank;
2 - filler neck;
3 - vent;
4 - low oil level sensor;
5 - tube oil indicator;
6 - connector fuel hose;
7 - the oil pump;
8 - a safety valve to 13.8 kPa (prevents the gasoline in the oil pump through the exhaust valve);
9 - the fuel pump;
10 - the fuel filter;
11 - the carburettor;
12 - wire (blue-gray) to block the alarm and protection.

The second external system is located on the left side of the crankcase. Built-in valve mounted in a short piece of hose connecting the two pipes. The valve should be positioned vertically, and the arrow should face down. This system removes the excess fuel and oil from the crankcase to the cylinder № 1 (top) and re-takes the combustion chamber.

The third system - internal - consists of one non-return valve in the intake passage of the cylinder crankcase number 2 (bottom). The valve must pass fuel to the inlet conduit, but not in the opposite direction to the crankcase.

All recycling systems have non-return valves. external system valves are mounted either directly on the crankcase or through recirculation valves internal system - in the crankcase cover.

valve side with one hole - of the inlet. The liquid should come into this hole, but does not flow out of it. Side valve with two or more holes - the outlet portion. Liquid here should only follow.

It can be checked using a syringe and a small length of hose. Subject to replacement of any nozzle that does not pass fluid in either direction, as well as any valve, a liquid permeable or impermeable both directions in the wrong direction.

In our case, we examined the available valves, trying to look inside the channel. The light does not shine through. This meant that the locking nylon ball was intact and in place. When the fine necessarily soft wire only we tried to move the ball, in some valves, he almost did not move, as the saying goes - "soured". Rinse valves pure gasoline, we regained their mobility.

Before this operation was washed with pure gasoline and the whole engine. After that reliable operation of the motor at idle and at idle is fully recovered.

How not to spoil porridge with oil

The second new system, which can face our vodnomotornik on imported outboards - this oil injection system. It does not need any preliminary calculations as to how much fuel to the tank with clean gasoline should be added. Clean oil is poured into a separate tank on the motor, and further fuel mixture of oil and gasoline in the required ratio for this moment preparing automatically. It is very convenient. Moreover, the oil consumption is reduced, as at idle and low loads it requires less; Again, do not suffer from the environment, the engine is less smoke, less soot is formed in the engine, not "salted" candles.

Generally company «Mercury Marine» employs four injection system:

1. Auto Blend II, which pre-mixes fuel oil and gasoline ratio 1:50 constant at all speeds and loads. She is now out of production, and it can be found only on models with capacity of 5-25 hp up to 1996-1997 years. release.

2. The system, which provides a constant ratio of 50: 1 at all speeds and loads on the motor; placed on the 40- and 30-horsepower 4-cylinder engines «Jet».

3, 4. Both the system of controlled composition of the fuel mixture. They have structural differences depending on the capacity and number of cylinders (for example, in the 4th system includes a control module electric oil pump), but their main task - to prepare the mixture with an oil content varying depending on throttle position and engine speed. Therefore, at full throttle fuel mixture will have an approximate ratio of 50-60: 1, and in the idle mode and slow speed of about 80-100: 1. The smaller the engine load, ie. E. The lower the torque and the smaller the throttle opening, the less oil is supplied. And vice versa.

Dual control oil pump capacity (it is driven by the crankshaft and is coupled with damper rod) is necessary for an adequate supply of oil under any load variations. For example, when the maximum modes, will be greater than the open throttle, the more oil will be supplied to the fuel even if the engine speed remains constant.

Another distinctive feature of the automatic lubrication system for motors «Mercury» is that the oil is not injected directly into the crankcase, some engines as other companies, and is supplied to a carburetor and fuel pump enters the engine with gasoline already.

It is this system of regulated oil supply and used in our «Merc-40." When it came time to go to refuel pure gasoline, we are every hour and a half, began to look back and to look into the measuring tube of the oil tank on the hood. The tank volume of about 1.5 l is calculated on 4.7 hours of operation at full throttle. We are alarmed that neither an hour or two no oil level in the tank, we have not noticed. However, we did not go at maximum capacity, but still - some oil consumption had to be! An unpleasant chill went on the back of any vodnomotornik knows what threatens the work of the two-stroke engine on pure gasoline ...

Remove the bonnet. We note that the oil level in the tank is actually slightly declined, but we do not see the reason that the glass tube of the indicator shows only what is happening on the lower two-thirds of its height. Now fine! But then we notice that the engine sump oil poured inside. What's the matter? Where does it ooze? A cursory inspection does nothing.

That oil, which we see in the pan, was hit in the engine, but there is not horrible. This means, for some reason, the engine had to work "on a starvation diet." This is serious. We must look for the cause. And yet - for hedging - pour oil from a spare kanistrochki 1:50 directly into the fuel tank. So calm.

If in any doubt to the proper operation of the oil injection system - to find out why - go for the traditional way of cooking fuel mixture. It is our advice to you!

We go back to the parking lot and be audited in all oil injection system. A careful examination has given nothing - all in perfect condition.

For hedging hold benchmark oil pump. Take a measuring cup, just is graduated on the volume to 50 cm3, and accurate electronic tachometer. By the motor during the test we connect a fuel tank with a mixture of 1:50.

Then disconnect the oil pump outlet hose from the connector on the safety valve (see diagram.) thus it is necessary to plug the hole firmly that there was no leak.

Tachometer, attach the clamps to the high-voltage wire of the first cylinder candles. Disconnected discharge hose drop into the prepared container. Then disconnect the oil pump shaft from the control arm. We rotate the lever clockwise
clockwise until until it is against the oil pump, and we fix the lever in this position.

Oil pump device.
1 - fixing screws;
2 - oil pump housing;
3 - External O-ring;
4 - Internal O-ring;
5 - direct plug;
6 - a plunger (sliding sleeve);
7 - rod with a flange;
8 - the drive roller oil pump from the crankshaft rotation;
9 - a control lever connected to the throttle mechanism of the carburetor.



The circuit arrangement of fittings and drain screw to remove air bubbles from the oil pump.
1 - nipple discharge hose;
2 - drain screw;
3 - the inlet hose.

Start the engine, giving it to run at 900 rev / min for 10 minutes exactly. If immediately after stopping the engine, the volumetric bottle at an ambient temperature of about 21 ° C should be about 7.9-9.4 cm 3 oil. We fit into the norm. This means that the oil injection system is operational and has the necessary performance.

When disconnecting or replacing any hose (this should be done carefully so as not ruptured or not to pull the hose, do not compromise your system for leaks). Because the system is necessary to remove any air bubbles that may prevent proper operation. Therefore, the oil pump placed under the cloth, unscrew three or four turns the drain screw (see. Diagram) and produce oil up until not stop the appearance of bubbles in the inlet hose. Screw then tightened to 2.8 Nm.

If there is air in the exhaust hose, it is necessary to start the engine on a mixture of 1:50 and run until the bubbles disappear. Of course, for these operations is better to have a transparent hoses. It is important each time adjustments to synchronize the length of rod oil pump to align the marks on the oil pump lever with embossed mark on the oil pump housing.

Once our manipulations in the reservoir oil level has dropped to almost 1/7 of the total volume and close to critical, when the alarm should be triggered insufficient oil level. Start the engine, and, indeed, in 15-20 minutes, when the level of close to about 210 ml, the buzzer is activated. This stock engine can run at full throttle for about 30 minutes, but it is better not to bring up this and immediately pour the oil into the tank until full.

We turn away - with great difficulty - the fuel cap and find that it has been wrapped with a warp, which is why the sealing rubber gasket strongly "jams" and when tilting the motor portion of the oil leaking into the sump. So, the cause of the oil - not in our accuracy, the motor is not to blame!

После полной заправки осторожно заворачиваем пробку и проверяем герметичность бачка при откидке мотора. Все в порядке! Вентиляционный клапан наверху бачка обеспечивает выпуск паров масла в атмосферу и предотвращает его выливание при откидывании мотора.

After complete filling gently wrap plug and check the tightness of the tank when the engine otkidke. Everything is fine! The vent valve at the top of the tank ensures the release of oil vapors into the atmosphere and prevents it from spilling out when tilting the motor.

Life after death
This is the second life of the propeller. Completely "killed" on the rocks or the screw is usually thrown away, or take the place of honor in the home "Museum of Glory". But do not rush to get rid of it, one of these screws have continued to bear faithful service.

Approaching deadline for the running of our motor, when he is ready to show all that capable. At this point, it will be necessary to check all adjustments, including the carburettor (on the running-in period was designed for a few more rich mixture), and the operation of the ignition systems and power fully synchronized. In this regard, we often wonder how to make it better? Maximum true results can be obtained on the go, at full mode, but fine adjustment in such circumstances is difficult to achieve. Therefore, we are reminded of the way the test screw, the recommended once upon a time the company «Mercury Marine». What is this method?

Tattered screw is not discarded, but is cut first approximately 1/3 of the diameter, is mounted on the engine, and in the mooring mode, the engine on the front door. Emphasis screw quite significant, so the ship at the pier must be securely attached. With precise electronic tachometer speed are measured and gradual trimming the propeller blades adjusted its diameter up to 1/2 of the original. The main thing is that the engine at full throttle could develop speed, close to the nominal. In this mode, and performed all the necessary adjustments. Later, no debugging test screw is no longer required. With it, you can monitor the motor performance from season to season. As he wear test speed will gradually decrease, and a sharp decline in its sign will close motor failure.


In our test case, the speed of measurement to continue to grow slowly, which means that the motor is not yet finished running.


We live in a new way
Over 35 hours of working together we have learned a lot about our new acquaintance. And we are sure that there is still more discoveries and revelations. For example, we were surprised to find that the same motor used items as metric and inch thread. As the motor is only suitable, native: even the details (or units) of the same model, but released at different times, may not be appropriate. When ordering spare parts, carefully read or interpret the part number. For example, marking the carburetor WMV-7-3-3246 means that this model series carburetor WMV number 7, has the third (counting from the top), released in the 324th day of 1996 and is required to inform the engine room.

Even in such seemingly little things like laying oil drain plug holes in the gear unit, must be treated carefully. Instead of accidentally lost when changing navigation after the gearbox oil fiberplastovoy pads we put a rubber sealing ring from the "Vortex". Reducer when stored in a dry place in winter flowed; replaced in the spring on a firm - after three months of operation and parking lots on the water in the gearbox is not a drop of water. And such examples are many.

Although we have learned a lot about our new «Merc-40», for 35 hours to examine its versatile character, of course, difficult. We will continue this interesting introduction. Detailed findings do early.

Obviously the main thing - «Merc-40» modern reliable motor. Ideologically, for us - this is another technique, which requires a different approach, new thinking long been commonplace.

Nodes electric motor is mainly concentrated on the right side of the engine

Konstantin Konstantinov

In preparing the material used special reference books for corporate service engines.

The editors thank the company "Mercury - NIITM" for providing the engine and help in preparing the material

Source: Boats and Yachts №187

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