Adjusting the STIHL grass mower carburetor. STIHL fs 38 on the STIHL lawnmower

Adjusting the carburetor of the STIHL grass trimmer fs 38

If you often encounter the need to mow grass on the site, then you can use modern devices on the type of trimmers or lawn mowers. Among other solutions on today’s market are lawn mowers, with which you can maintain the surrounding area in a well-groomed state.

As the 1 st advantage of lawn mowers is that it is not tied to the power supply on the principle of electronic machines. But it can be used even in rough terrain and inaccessible places, including areas under bushes.

the lawnmower is more non-hazardous because the introduction of electricity is always accompanied by the possibility of electrocution. The choice of the right grasshopper is key. For this you should familiarize yourself with at least one of the models. Among the others on the market is the mower “STIHL FS 55”, reviews of which should read before buying.

Main carburetor problems and malfunctions.

Filter mesh. There are two problems with this element more often than not:

To find the causes of damage unscrew the fuel filter cap to remove the strainer. If it is just clogged with dirt then it is better to rinse it in petrol or blow it out.

If there is visible damage on the strainer a new one should be used. There may also be damage to the fuel supply pipe (when repairing this element it is a good idea to check it).

The starting device of the carburetor in most cases does not function because of clogs. Use acetone or the same gasoline to flush it.

Blowing out clogged carburetor parts with compressed air is an acceptable and convenient repair practice.

Throttle body, carburetor component joints, intake or exhaust line. all of these parts are subject to depressurization. Check for sure can be done in a primitive way. put soapy foam on the problem area.

How to adjust the carburetor on a chainsaw. chainsaw service. Part 11

How to start this STIHL chainsaw MS 250 (without primer) in general the correct way. Bought it a long time ago, don’t use it much. Last year I decided to use. As before, with the choke closed, pulled the cord 3-5 times. no “contractions” (after which the choke opens and a normal start is made). Thought I overfilled it, filled the spark plug.

Took it in, wiped it down, burned it, “vented” the cylinder. It doesn’t start again. Repeated the procedure, then put a new spark plug. the same effect, no start. I went to the service. they twisted something, started and said: on saws without primer, when starting from cold, you do not need to wait for grabbing, enough two or three times to pull, and then open the valve and start. Is this true??

The unit, of course, sensitive to “priming”, but the flash should be. If the saw is in good working order and the carburetor is correctly adjusted. The starting procedure is the same for all saws. Only one thing is not clear: if you vented the cylinder and put another spark plug, it should have started from the middle position (if there was no suction).

Really, there was one case in my practice when the tool started cold without suction, then hot also with a half revolution, idle, acceleration, traction. everything was normal. But that was one such 250.I have a few dozen of them. You can try for insurance at first, as they said: do not wait for seizure, and if it does not start (most likely), then, as necessary.

I cleaned the filter first of all, and there was no special dust and the chain was sharpened, but it does not want to saw. The tip of the tire cuts relatively normally, but when full tire, the rpm drops. What to do?

Resharpen by all means! It’s just a sign that the left and right sides are differently sharpened (or one is dumber than the other). I think all the problems go away. If the chain is properly sharpened (or new if you have one) and nothing changes, then. the carburetor needs adjusting.

I’ve had my STIHL MS 250 for three years now. Since this spring, after not draining gasoline from the tank for the winter, problems started. After a week of not using it, it starts fine. But when you run it, the mid-range rpm is gone. You’ve got to accelerate really well all the time. But the interesting thing is, the next day the problem’s gone.

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Fuel supply malfunction. If the spark is normal, check the fuel system. Preferably all the way from the intake to the carburetor. There may be slime in the intake, try replacing. But especially thoroughly clean and check for damage to the carburetor.Well, if the other day works well then air suction, I think there is no. And also check the quality and proportion of the mixture.

I can’t get the saw to fire. mix leaks through the muffler. I shut off the gas pedal, it runs like clockwork. Left it for 3 hours came back and it was like this. It looks like there’s a spark, but it won’t start. Anyone have had this problem??

Your fuel system is not mixing properly, maybe there is air intake. Recall what else has been torqued or unscrewed. Probably not a tight connection.

Changed the crankcase on the STIHL MS 250 chain saw. After assembly, gasoline is leaking by a stream from the tank and rubber tube connection. The crankcase is original, the tube is old, inserted correctly. Is it a shrunken tube and it needs to be replaced or is it a tube and tank joint that needs to be sealed with a thread sealant of some sort??

adjusting, stihl, grass, mower, carburetor, lawnmower

Change suction hose. It fits snugly into the housing, at most a little oiled when installed.

Can I install a STIHL 250 chain saw with side plates?325″? If so, what are the tire and chainwheel part numbers.

On the MS 250 you can fit a 0.325. 1) art. 30050005009. Tyre 14″ (35cm) 0.325″ 1.5 56 links. STIHL 025. 2) item. 30050004713. 16″ (40cm) 0.325″ 1.6 62 links. 025. 3) art. 30050084717. 18″ (45cm) 0.325″ 1.6 68 links. Chains respectively: 1) art. 11230071032. Chain set. wheels 325″ 7z. 2) art. 11230071031. Chain set. 325″ 8z wheels. 3) item. 11236402074. Prof. chain. 325″ wheel 7z.

How do I replace the clutch springs and clutch weight holders without disassembling the whole saw??

You have to remove the clutch, otherwise there is no way.

Stopped oiling the chain on a 250 Stihl, I think I cleaned everything, poured warm oil, started indoors, does not go, on a windrow so broke the chain, what are the thoughts?

On the lubrication of the 250. the pump was pulled out? They have a characteristic clogging of the oil system there from time to time, especially if the saw is used in construction work. You try these steps: Take the plugs out of the shock absorbers, unscrew the 3 screws that are underneath and another one on the right side of the handle.

Disengage the frame handle, move it slightly to the side so you can reach the oil pump connector. Remove the connector screw. Saw with plugs facing down. If no oil is leaking from the hose, take it out of the bottom of the cut-off saw with the oil filler plug and clean the hose. Reinstall, oil should flow.

Screw in the oil pump with a long M5 screw. Use pliers to pull the pump out of its seat, using the pliers as a lever, resting against the casing or frame, whichever is more convenient. Check and see if there are fine filings in the longitudinal groove on the pump housing and remove them. Check that the pump rotates without faltering, put it back in place using the same long screw and tapping it with something.

If you own a STIHL MS 250 saw. No oil flow for chain lubrication, chain and bar have overheated. replace both?

There is nothing wrong with your tire, it is not overheating, but zone hardening. What to check: The drive worm itself. you have to remove the clutch. Check visually for damage. If the worm is damaged, check the pump if it is jammed. If everything is normal here, check the suction side.

Do-it-yourself STIHL 250 chain saw repair

What is the preferred chain for this saw?? 3/8 or 3/8P ? I read somewhere that they are interchangeable. Is this true (the bar is marked 3/8P) ?

I want a longer guide bar (40cm). The manager at the store advised to change the chain pitch from 3/8p to 0.325 justifying it on the grounds of better performance. How smart is that?? What’s the best sprocket, bar, chain?

How to Adjust the Carburetor on a Chainsaw

Before adjustment, the filters must be thoroughly cleaned according to the maintenance instructions.

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Further adjustment of the lawn mower carburetor with their own hands is made adjusting screws. There are three in total:

right (L). adjustment of the fuel mixture for low revolutions.

Find the highest rpm at idle speed. To do this, slowly turn the screw (L) to the right and left.

adjusting, stihl, grass, mower, carburetor, lawnmower

How to adjust the carburettor on a STIHL 55 trimmer.

to adjust, turn the screw a quarter of a turn anticlockwise.

the lower one (T) is responsible for adjustment of the engine at idle speed.

To correctly adjust the idle speed is characteristic:

  • stable cold engine operation;
  • not overdrive revolutions of the hot engine;
  • for the trimmer head‘s large RPM margin;
  • stable engine operation during changes of position (sudden raising or lowering of blade).

left (H). adjustment of mixture at high revolutions. (The screw should be adjusted last.).

The left-hand screw (H) determines the overall adjustment of maximum rpm, engine power, temperature and gasoline consumption.

Setting carburetor Lawn mower with the last screw is performed as follows:

  • Open the throttle to full, while giving full throttle. Turn the screw clockwise until the revolutions drop (in this case, orient by ear).
  • Turn the screw as slowly as possible counterclockwise until the engine is uneven.
  • Then turn it back just a little, barely hearing a steady, even operation.
  • For a more obvious application of skills, it is more convenient to review the work of an experienced user:

Interesting that from the point of view of the author of the video, the tuning (its correctness) is determined by the color of the candle, and not only by the rpm and stability of the engine.

The correct setting of the carburetor with their own hands in this case. combustion of the fuel mixture without residue, the color of the candle should be light brown.

How to set the ignition on the trimmer

Often the owners of gasoline cosmos are faced with the fact that the ignition does not work on their equipment. In most cases, the problem is really with this node. To fix it, you need to adjust the ignition on the grass trimmer. But at the same time, it is not uncommon for the ignition coil to be in good condition and the breakdown to be looked for elsewhere. The ignition system is designed in the same way on four-stroke and two-stroke internal combustion engines, so you can troubleshoot in the same way. In addition, the technology of different brands have almost the same design of this essential component of the tool, which means that the process of regulation will be the same, as for trimmers Union or Brigadier, and for Huter, or for samples of other brands.

Every STIHL lawnmower is strictly designed for the intended use of its engine power. The manufacturer strongly advises against retrofitting or improving the grass scythe device in any way without the aid of others. Therefore, before you take a STIHL lawnmower, you need to correctly determine the upcoming work front.

It is not at all impractical to get a powerful grass trimmer for repetitive mowing of grass in the clearing, for this is completely sufficient lightweight gasoline or electronic models of mowers.

Problems and solutions. repair with their own hands

But what to do if you suddenly could not avoid the breakage of the mechanism? We will not look into the causes of this, but it will not be superfluous to consider possible problems that may arise with the mower, as well as methods of fixing them with their own hands.

The engine does not start. If you are faced with this problem, then initially you need to assess the amount of fuel in the fuel tank, maybe the problem as such does not exist, and you only need to add fuel and continue working. By the way, the fuel used by the mower is worth special attention, because its quality determines the life and quality of the mower. Experts recommend gasoline AI-92, not lower.

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Another likely cause of engine instability is a dirty fuel filter. It should be carefully inspected, cleaned if necessary. If the filter cannot be repaired by yourself, you should replace it with a new one.

Do not forget about the air filter either, clogging of which can also lead to tool failure. To avoid this, the part is removed and washed in water with detergents, or in gasoline if there is no access to water supply.

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Then the filter should be carefully rinsed and dried, paying close attention to the structural integrity. Before mounting the part in the mower, lubricate it with a little oil. However, if you do not want to bother with cleaning the machine, then we suggest you familiarize yourself with a mower with mulching function, because it will not only mow the lawn, but also prepare a further fertilizer.

The spark plug may also affect the performance of the engine. It is necessary to unscrew it and check its condition, if necessary replace it with a new one.

If after all these manipulations, the engine still does not start, then you can resort to the tips of experienced craftsmen, who have used them in practice.

It is necessary to adjust the speed with the carburetor screw. Put the mower in such a way that the fuel hits the bottom of the carburetor. To do this, the tool is placed so that the air filter is on top.

Then you need to remove it and pour some fuel into the carburetor, then install all the parts in place. The engine should start.

You can pull the starter knob, while closing the carburetor choke. Then open it and pull the starter a couple more times. This is a fairly universal method, proven over the years.

These tips are not a panacea, but they are quite effective and useful.

Mower stops shortly after starting. The primary cause is improper carburetor adjustment. It’s easy to tell if there is a problem. you will feel a strong vibration when the mower works. You can correct the problem yourself by looking in the manual for a detailed description of the problem and how to fix it.

Pay special attention to the fuel line, it is often the reason for the tool to choke. Check and clean them regularly.

Smaller parts like the cable or the fuel intake hose can affect the stability of the machine. So you need to keep an eye on their condition, check for cracks and small punctures.

Many might be put off by the relatively high price of a STIHL machine, but when you think about it, it is more important to choose between reliability and a good product and economics that detract from the quality? But if you set the goal to save money, then we offer you a variant of lawnmower with your own hands, collecting the device with your own efforts you will know all the nuances and the structure of the tool.

Of course you can also buy cheaper Chinese products but in this case no one can guarantee the results of the final work and the durability of the mower, which is often very short for such models. So it’s better to buy a mower from a reputable company once, which is certainly STIHL, and enjoy stable operation for many years of service.

Signs of imbalance

Adjustment of the carburetor, of course, is done when the unit is made. Adjusting the Benzokosa Texas 330 carburetor. Usually owners learn about the need to adjust the fuel supply with their own hands only after serious breakdowns, during the repair of which the module was removed and, for example, cleaned.

Signs of malfunction in the settings are as follows:

  • it starts, but the engine stops here. because the engine can only work when a certain amount of gas is fed with a very “bad” fuel, in other words, blocking the supply channel, the engine stops;
  • Very high fuel consumption, lots of exhaust. result of incomplete combustion. In this case there is a lot of fuel and the mixture is extremely thick.


belongs to the lightweight group and is the optimal complement to a lawn mower for cutting hard-to-reach areas, along paths, under trees and bushes. With the STIHL mobile petrol cutter you can mow soft overgrown lawns and lawns quickly and keep your lawn tidy at all times.

STIHL FS fifty-five Motocross lawn trimmer mower. it won’t rev, it shuts down, rebuild carburetor

STIHL FS fifty-five Motocross weed trimmer No speed, throttle, carburettor overhauled Thanks for watching.

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