Chainsaw fuel pump Shtil 180

What carburetor is used on the Shtil 180 chainsaw

The Shtil 180 chainsaw is equipped with a Japanese Zama membrane-type carburetor. Some users are confused by the inscription China on the carburetor. Yes, indeed they are assembled in China. But the plant belongs to the Stihl company, and the quality still remains at a high level. However, the chainsaw also has Chinese copies with corresponding carburetors. But such saws are usually cheaper than the original.

To sum it up.

In fact, as you can see, there are quite a lot of reasons for the breakdown of the Shtil 180 chainsaw, and at the same time, there are also quite a few solutions to this problem. If you are faced with this situation, then simply follow all the recommendations written above and then, undoubtedly, you will be able to repair your device, and it will delight you with its work for many years to come.

Read:

In fact, as you see the causes of chainsaw collapse, Stil 180 is quite a lot, and at the same time, the solutions to this problem are just as good. If you are faced with such a situation, just follow all the above recommendations and, undoubtedly, you will be able to restore your device and it will delight you with your work for many more years.

How does the Shtil 180 carburetor work: device, principle of operation

The main components of the Shtil 180 chainsaw carburetor include the following components:

fuel pump (with internal diaphragm);
main (membrane) chamber;
diffuser;
throttle and air dampers;
needle valve;
fuel jets;
nozzle with valve;
idle speed adjusting screw.

The principle of operation is this. The chainsaw crankcase is connected to the fuel pump in the carburetor by a special channel. Due to the alternating stroke of the piston, a vacuum is created in the engine crankcase. Due to this, the diaphragm in the fuel pump rises and the valve opens to supply fuel to the carburetor.

Next, the fuel passes through the filter element (mesh) and enters the main chamber through a special channel. A control membrane is installed in this chamber, which regulates the fuel supply by pressing the rocker arm, which in turn lowers the needle valve.

Raising the control membrane is responsible for the vacuum that occurs in the carburetor diffuser due to the rotation of the air throttle valves. As soon as the engine starts, the mixture needs to be leaner. We lower the air damper, the vacuum in the diffuser is minimal, and the membrane falls into place.

From the main chamber, fuel enters the diffuser using a nozzle with a check valve, or through idle jets (when the gas throttle is closed). There it is mixed with the intake air and the finished mixture enters the engine cylinder. The check valve prevents air from the diffuser from entering the main chamber.

How to check the performance of the fuel pump

There is a membrane in the pump body, which during movement ensures the supply of fuel to the carburetor and engine. If the Stihl MS 180 chainsaw does not start, the diaphragm may have ruptured. You can check its integrity by removing the pump cover. If any defects are found during the inspection, the membrane is replaced.

Chainsaw repair Shtil 180

Adjusting the carburetor of the Shtil 180 chainsaw

Usually, special screws are responsible for the quantity and quality of fuel entering the diffuser, by adjusting which we change the cross-section of the fuel channel. But on the Shtil 180 chainsaw carburetor used, to facilitate the operation of the saw, these two screws are missing.

The channels are designed in such a way that the optimal amount of fuel enters the diffuser at all engine speeds. And the LD screw is responsible for the adjustment here, the rotation of which regulates the air supply to the idle jet. Due to what the engine speed changes.

So, to adjust the carburetor of the Stihl 180 chainsaw you will need a regular flat-head screwdriver and an electronic tachometer (optional). The adjustment algorithm is as follows:

Check the air filter. If necessary, replace the filter element.
Screw the LD screw counterclockwise until it ends, and then unscrew it 2 turns. Attention, left-hand thread! To access the screw, there is a hole for a screwdriver on the saw body. Start the engine and warm up for 5-7 minutes.
By turning the LD screw slowly clockwise, we arbitrarily adjust the idle speed. 2 situations are possible: The engine speed at idle is very low. The engine does not idle. Turn the LD screw until the saw starts to rotate, and then turn the screw 1/2 back (the chain should stop).
The saw spins at idle speed. In this case, slowly turn the screw counterclockwise until the chain stops, then turn the screw another 1/2 turn in the same direction.

If, after all the manipulations with the carburetor settings, the chain continues to spin at idle, the saw should be returned to the dealer for a service center.

The video below shows detailed adjustment of the carburetor of the Stihl 180 chainsaw using an electronic tachometer.

Who can repair carburetors?

repair cleaning carburetor stihl 180.

Everything said below applies to any models of chainsaws, including gas trimmers, scythes and other equipment. Adjusted, of course, for design features.

There is an opinion that it is better not to climb inside a chainsaw yourself. For those who are used to working with a hammer and sledgehammer, this may be true. Otherwise, any more or less neat person whose hands do not shake can fix any problem with his work. In general, this is a job available to anyone.

Of course, it happens that the problem cannot be solved on its own. And you need to contact the service center. But firstly, 90% of malfunctions are usually solved by simply flushing the jets or, in the worst case, replacing the membranes or adjusting the needle, and secondly, in the worst case, even if you are desperate, the carburetor removed from the saw can be easily replaced.

Currently reading: Jigsaw cuts crookedly - how to fix it

Repairing the carburetor of the Shtil 180 chainsaw

The main malfunctions of the Shtil 180 chainsaw carburetor include the following.

Gasoline does not flow into the carburetor. The banal reason is fuel pump failure. The diaphragm has lost elasticity or become thin. This happens due to fatigue of the material after prolonged use. As a result, when there is a vacuum in the engine, the diaphragm does not rise and does not open the fuel channel with the valve. It can be replaced with a spare one from the repair kit by disassembling the carburetor.
Gasoline may also not flow due to a clogged filter element (mesh) in the channel between the fuel pump and the needle valve. It can also be treated by replacing it from the repair kit.
The carburetor is overflowing. It is not difficult to guess that the problem lies in the main camera. Dirt particles fall into the cavity between the needle and the channel, i.e. the valve does not completely close the channel when needed and the chamber floods. Very often the membrane ceases to perform its functions due to stretching (natural wear). As a result, when lowered, the membrane does not fully lift the needle, and fuel continues to flow. The main membrane is also included in the repair kit. Replacing it won't be difficult.
Very often, after winter downtime, owners of Shtil 180 chainsaws encounter difficult starting. In this case, the valve in the nozzle is stuck. The manufacturer recommends that before storing the chainsaw, burn off the remaining gasoline in the carburetor. Gasoline is prone to evaporation and during long-term storage, engine oil remains in the carburetor, upon contact with which the injector valve begins to stick to the body. As a result, fuel does not enter the diffuser. Since the nozzle is not included in the repair kit, you have to knock it out and wash it thoroughly. This must be done very carefully.
If the idle jet or injector is clogged, it is enough to blow them out with compressed air. Or wash it in gasoline, in 90% of cases this helps. But you cannot use needles or wires, because... there is a risk of changing the flow area, thereby changing the throughput of the jets.

A common problem due to which the Stihl 180 is unstable is the loss of the retaining ring on the throttle valve axis, as a result it begins to dangle and play, which in turn leads to interruptions in operation.

So, you decided to remove the carburetor and carry out diagnostics. The removal procedure is as follows:

Press the gas trigger and lower the choke lever down. Turn the latch and remove the chainsaw cover.
Using a socket wrench 8, unscrew both fastening nuts and remove the air filter with the housing.
Remove the gas draft (throttle valve) of the carburetor.
Disconnect the cable from the control lever
We remove the engine control lever from its place. At the same time, disconnect the air damper rod.
Pull the carburetor towards you and remove it from the studs. Don't forget to disconnect the fuel supply hose.

A more detailed and visual algorithm for removing a carburetor from a chainsaw is presented in the video.

As for disassembling the carburetor of the Shtil 180 chainsaw, everything is simple. 1 bolt is unscrewed on the fuel pump cover and 4 bolts on the main chamber cover. This is enough to change all the necessary components from the repair kit.

After disassembly, the carburetor must be washed in gasoline, and the channels and jets must be blown out with compressed air. Under no circumstances should the carburetor be blown under high pressure and in the assembled state. Otherwise you may stretch the membrane or diaphragm. The carburetor will stop working properly.

In order to assess the condition of the filter mesh and membrane, you need to perform the following sequence of actions:

Unscrew the screw.
Read also: In pursuit of the German “Unimog” (Part 2)Multi-purpose all-wheel drive vehicles AMO ZIL
We assess the condition of the membranes, remove dust and dirt, and if necessary, replace the membrane with a new one.

Everything under the membrane should be clean

There should also be no dirt on the membrane

We check the condition of the filter mesh for dirt and clean it if there is any.
We put everything back together and disassemble the carburetor on the other side. After unscrewing the 4 bolts, remove the cover, remove the membrane and assess the condition of the insides.

A total of 4 screws need to be unscrewed
To check the serviceability of the fuel supply, put the hose on the fitting.
We blow into it with our mouth, while using our fingers to open the needle valve, everything should work correctly.
We blow out 2 holes in the jets with the same hose, they should blow easily, without excessive force. If necessary, simply clean with regular WD-40 cleaner.
We remove the nozzle located on the right and clean it with a thin wire from the reverse side.
We clean and collect everything. When installing the cover, ensure correct installation. See photo below.

As for the repair kit for the Shtil 180 carburetor, it includes a set of gaskets for the covers, a diaphragm and membrane, a needle valve, a rocker arm with an axle and a spring. The price of such a kit is from 100 to 400 rubles.

Removal and installation algorithm

In cases where it is necessary to clean the Shtil 180 carburetor or disassemble it, you will first need to remove the assembly from the chainsaw. This must be done in compliance with a certain algorithm of actions:

Place the protective cover for the chainsaw on the bar.
Remove the top cover of the chainsaw.
Unscrew the two nuts securing the air filter and carburetor.
Remove the air filter housing.
Disconnect the wire from the engine control lever.
Carefully remove the lever from its seat in the housing, while simultaneously disconnecting the air damper rod from it.
Pull the carburetor towards you and disconnect the fuel supply, as well as the throttle linkage.

To install the part in place, follow the reverse order of the algorithm.

When removing and installing the chainsaw engine control lever, you should be extremely careful, because the seat on the saw body is the weak link of the saw, and very often inexperienced users break it.

Advantages and disadvantages

Zama carburetors are very reliable and easy to use. Specifically, the Shtil 180 chainsaw has a carburetor, which does not have screws for adjusting the quality and quantity of the mixture, as we are used to. One screw makes adjustment much easier.

A diaphragm carburetor has no significant disadvantages. With such a carburetor, the chainsaw works in any position. For side cutting, vertical cutting, etc.

Despite the above-mentioned advantages, the carburetor is sensitive to fuel quality. In addition to clean air from the air filter, purified fuel from the gas tank must be supplied to the carburetor. But this is not always possible, so at least once every six months it needs to be cleaned and blown out.

Frequent breakdown of the Stihl carburetor and how to avoid it

A common cause of carburetor failure on a Stihl chainsaw is a stuck valve in the nozzle. The reason for sticking is a violation of the storage of the chainsaw, or rather the Shtil 180 manufacturer’s instructions for proper preparation for storage.

As follows from the instructions, before long-term storage, it is necessary to drain the fuel from the tank, then start the saw and burn off the gasoline from the carburetor. Failure to comply with this elementary rule entails the following consequences. The forsknui valve, being in direct contact with the fuel, sticks to the body, because.

How much does a new carburetor cost?

The average price of a Zama carburetor for a Shtil 180 chainsaw on aliexpress starts from 400 to 900 rubles. The question is whether these are original carburetors. In online stores the price is already higher, from 700 to 3000 rubles.

Shtil 180 chainsaws are in great demand in Russia, primarily due to their reliability. The carburetor is no exception and is also quite reliable and unpretentious. Carburetor adjustment or repair is required only after long-term use, no less than 5-7 years (at average load). The setup process itself has been simplified as much as possible by Shtil engineers; this is the first chainsaw in which only one screw is provided for adjustment.

Tags: chainsaw repair calm

Comments 40

Yesterday, for some reason, the crankshaft bearings jammed during startup. I sorted out the dirt there and washed and lubricated everything. everything started spinning. assembled in reverse order. The saw does not start, there is a spark, there is gas. there is a current one BUT. assembled using transparent silicone sealant. I assembled it and after an hour I started trying to start it. is silent. and also poured zero under the candle. Maybe it won't start because the sealing is bad? The new saw was used 5 times in total.

dirt in the bearing means dirt in the gasoline! I don’t even know, try a different sealant. But that’s probably not the reason!

in the first part in the photo you can see a bottle with 80% oil that they are scorched because of this and are scuffed

How did you determine that it was scorched?

Container color print quality. Well, a great video right away.

Well, you are an “expert”! 1) The label is not really visible in the photo, but you saw the quality of the print and identified a fake, or rather, YOU SAW IMMEDIATELY) 2) The color of the bottle can distort the camera in any way, depending on the white balance settings and the sensitivity of the camera itself. 3) The oil was not bought on the market, but from an OFFICIAL STIHL DEALER along with the saw!

They even repair chainsaws here))). And they say it’s a car site. I also have a calm, 290 ms, and I took apart the current oil hose and changed it

Nice chainsaw. It has been working for me since 2008 and there are no problems. I cut about 12 cubic meters a year to heat my house.

This is what it looks like, more or less, it’s just a mini bikini