Oiler adjustment screw missing . Can see some sort of smooth goged rotor which spins when engine running but apears to be nothing connectted to it to action oiler. Cant access a parts list to see whats missing.

MS291 Does NOT have an oil adjustment screw. It is an auto oiler. Make sure the ports are clean and oil is coming out running the saw with chain off. Then add a little canola oil to your chainsaw bar oil and thin it down. You will get a better flow. Stihl has a poor design on this model.

To begin with, let's start with the basics.

1. Are you using fresh gas? If not, you need to get some. If there is any old gas/oil mixture in the machine, remove it by pouring it into some sort of container.
2. If want to purchase a gas/oil mixture already mixed, a store like Home Depot or Lowes has quart cans at the correct mixures. 50:1 / 40:1 etc. and it's Leaded gasoline usually 91 octane.

Weedeaters will lose their carburetor adjustment over time because of vibration or the fuel mixtures may change. The carburetor settings are crucial for the machine to run properly.
Not all carburetors are the same, but which ever one you have, you will need a special adjusting tool to do this. You can find adjusting sets locally or here. https://www.amazon.com/HIPA-Carburetor-Adjustment-Including-21-Teeth/dp/B01FAAKN7E/ref=sr_1_3?ie=UTF8&qid=1467833656&sr=8-3&keywords=carburetor+adjusting+tool

Not To do this process, you will need to identify the 2 special

adjusting screws on the top or side of the carburetor.
The screws are highlighted as HI and LO. The HI allows fuel adjustment for the weedeater at full throttle. The LO is for the adjusting the idle.

Try these steps:
1. Adjust both screws clockwise until just seated (tight) using the correct tool (from a set similar to the one above)
2. Rotate the HI screw 1 1/2 turns counter-clockwise
3. Rotate the LO screw 1 turn counter-clockwise
4. Start the machine.
5. When it's running (spitting, coughing...) adjust the LO screw a 1/4 turn either way until you get a smooth idle.
6. Pull handle to run at full throttle. If the engine is sputtering then it's getting too much fuel....adjust the HI 1/4 turn clockwise checking to see if the engine runs smoother.
7. When you get the weedeater running smoothly, there are no further adjustments to be made. Just make sure you are using FRESH gas/oil that hasn't been sitting longer than 30 days.
Good Luck!




Once j

Well, the simplest cause is a plugged air filter. Insufficient air with the usual amount of gas causes a rich, smoky mixture. Clean the air filter and make sure it isn't clogged with grass clippings.

replace the injector in no 2 cylinder

Hi Charles Gregory.

When you clean your carburetor and remove the jet screws, you will first need to lightly seat the jet screws.
But before you lightly seat the jet screws count the number of turns it takes to seat the jet screws from their original position.
Be sure to mark the turns down on a piece of paper.
That way when you put the jets back in, you know to lightly seat them first and then turn them back out to their original position before you started.
Make sure your spring that goes on the idle screw is in place.
You can also use some "locktite" thread locking compound on the threads of the needle if the spring is missing.
Normally you will adjust your idle jet to 1/2-3/4 turn open from the bottom seated position.
Then you will re-adjust the low speed of the engine when the engine is warm by turning the idle screw in or out till the engine runs smoothly at idle speed, around 1200 RPM.
The high speed jet is adjusted to 1 1/2- 1 3/4 open from the bottom seated position, after the engine is warm.
Then re-adjusted by turning the High Speed jet adjustment screw in or out till the motor runs smoothly at high speed.
Alway use the "lightly seated" method if you have not changed the screw settings.
Please take time to rate me
Bud

Hello, If this is a push rod engine I had an identical problem with an engine in my 1988-1989 Jeep Wagoneer. It was a Buick V-8 and behaved exactly like your Ford engine.

On my engine it was weak valve springs. You could take your thumb and push on the valve spring while the engine idled and the engine would miss out. Turn it off and start it up and it would idle smoothly, rev it up and let off the gas and it would miss out and shake. You could also have hydraulic lifters (check your model) and they could behave like this. At idle the lifters would pump up, but the lifters may not refill fast enough to work the valves smoothly.

If you have hydraulic lifters they must be centered in their travel to pump correctly. Even if you have solid lifters the valve adjustment can affect engine performance.

Hi murban001,
From what you describe, it is running lean, and you should adjust your carburetor. Obviously if running with the choke it has more power, turn the high speed mixture screw out (counterclockwise) with engine running 1/8 turn at a time until it runs better. With engine stopped turn that high speed mixture screw in or (clockwise) until lightly seated,( but remember the screw setting before doing this). This is to check how much it is turned out. The high speed mixture screw should not be adjusted less than 1 turn out from a lightly seated position to prevent running too lean, as that could damage the engine because of overheating. The adjustment process is to turn the H screw in until it just starts to run bad now turn it out until it starts to run bad, adjust the screw in the middle of those 2 positions to get the ideal setting, a bit richer is even better to help cool the engine. The gas helps to cool the engine, but some people don't think of that as being the case. When you accelerate the engine, if it sort of misses or hesitates turn the L or idle speed mixture screw out a bit, adding more gas to the mixture help with acceleration. Hope this is helpful. Regards and good luck. Denis.

To check for proper oiling, run the saw at speed with the tip of the bar near a piece of cardboard--it should throw off a thin line of oil after several moments of running. Adjust the oil adjust screw CCW for more oil. The screw is usually in the lower front or underneath the engine. Remove the bar and chain first before adjusting anything and check the oil passages located in the drive end of the bar for plugging--especially the two small passages that go from the large oil holes out to the chain groove on both sides. Start the engine without the bar and chain--look at the oil port where the bar mounts next to the engine. It should ooze out oil with the engine running fast. If nothing at all, the pump, oil lines, and oil filter in the tank should be checked. When everything seems to be working, then adjust oil flow for best operation. Hope this helps!

Turn both screws CW to stops (lightly), then back out CCW 1-3/4 turns each. This a basic setting and both will need to be set leaner (CW) after the engine warms up. Remove the spark plug and check for blue sparks when the engine is pulled through. If nothing, try a new spark plug. If still nothing, try removing the stop switch connection at the ignition module and retry for sparks. If nothing again, replace the ignition module. Use a thin business card to set the pole gap (the magnets should be under the poles of the ignition module) when installing the replacement. If you get sparks in the first test, try spraying some carburetor cleaner in the plug hole, replace the plug, and attempt to start. If you get a pop or two, then you have fuel problems. Check the fuel lines for condition, check the filter inside the fuel tank for plugging, and tightness of the carburetor screws and nuts. Remove the muffler and check for plugging. Check the air cleaner for plugging. If it still won't run, then the carburetor should be removed, disassembled, cleaned, and fresh gaskets and diaphragms installed. Keep track of what went where as you remove parts. If the machine appears to have good compression, it should start. When the engine is warmed up, adjust the H needle to 4-stroke at high speed, but smooth out when cutting. The L needle should be adjusted to allow the engine to run fairly smoothly, but allow the engine to 'follow the throttle'. Idle speed should be set so that the string head does not turn, but keeps the engine running. Hope some of this will get you trimming again!

there is a little screw holding rotor to shaft rotate engine to spin rotor screw is on front of rotor on shaft