Need to know what carb screw adjustment need to be set at weedeater starts for about 4-7 sec then shuts down put new hoses on checked gas filter and cap checked out ok. i pump the ball about 10 times ,pull cord &starts for about 4-7 sec then shuts down,like no gas or electrical problem. i played with the screw settings & dont know where they shoould be set at . had carb all apart ,put in new plug doesnt seem to matter what i do it does the same thing . any thoughts?also when it starts the motor will rev up when u hit the gas and when it shuts down the gas hose from the tank is still full of gas

Here's a link to your owner's manual,look at page 26 for carburetor adjustments,I have 3 stihl's,a blower,weedeater and chain saw,had them a long time,never had to adjust the carb.What problems are you having?Clean your air filter or replace it if's real dirty and can't get clean,use 50;1 regular unleaded gas and oil mixture,put a new plug in it,same as you were using,Autozone has them cheaper than the Stihl dealer.Are you using your choke and throttle correctly when starting?On mine,I set the throttle,lock it in,put choke on close,pull a few times,no more than 5,then open choke and pull,it should start,is your spark plug getting oil-gas on it,if so then your flooding it at start up,use fresh gas mixture.I wouldn't adjust the carb. https://www.stihlusa.com/WebContent/CMSFileLibrary/instructionmanuals/FS160_180_Manual.pdf

buy a new carburator on ebay for 20.00,the diaghram and all the rubber hoses are shot,that is what ethanol does,eiher try a rebuild kit or wait 2 days for a new one

Use only fresh gasoline (alcohol free if you can find it). Purchase a top quality synthetic 2 stroke oil such as Lucas, Golden Spectra and mix it exactly as the manufacture dictates. Install a new accurately gapped plug and make sure the plug wire cap (boot) is pulled back to inspect the wire to connector crimp. Start it up as you normally would to allow the new gas and oil to permiate the system and if you cannot get it to stay running without the choke being on shut it down and squirt some oil into the carburetor and pull the trimmer over, if this makes it start everytime it does not want to start and it allows you to click off of run you have either low compression (rings are worn). or your carb is yet another victim of the geniouses that thought alcohol in gas was a super idea. Either way you can replace the piston and rings or the carb. both are almost not worth the time and cost anymore, a new carb for mine is $70.00, with a new piston and ring set being around $40.00 and a brand new trimmer the same as this one on sale at $130.00 it was an easy decision to buy new.

If you were able to find a screw to replace the one that was lost, it's most likely not a special screw. Tough to say what that screw was but if it's not tapered, it may be the idle speed adjustment.The idle adjustment screw has a spring under it to hold the setting after adjustment.
The carb will need all the orifices under the float bowl cleaned.
Be sure to drain the gas and run the engine til the carb is empty next time the generator is stored.

This is fuel starvation, replace the fuel filter in the tank, check the fuel hose up to the carb for signs of leaks, or cracks, if the carb has no anti tamper screws, screw the L screw out 1/4 turn to richen the mixture, if the carb has anti tamper screws you will need to get the special tool to adjust them.

Sounds like it is runing too lean, remove the filter from the tank ( on the end of the fuel line ) and replace, check all the fuel hoses up to the carb, any signs of cracking or fatigue, then replace them, if no better make a small adjustment to the H scerw on the carb, screw out approx 1/4 tur.

steps in adjusting a carb
1 take off the air filter case you'r carb will be under it
2 move choke lever to full choke the float should be closed move to to half choke there should be a small gap then move to run float should be all the way open 3 there is one more float in the back of the carb it uses a screw to open and shut the screw should be almost completely screwed in
4 put air filter case back on and if the problem is not fixed then its not your carb and is most likely in need of a new air filter,has bad gas or the fly wheel is not inline with the armature

That unit probably has a high side and a low side screw in the carb. Maybe, the screws are out of adjustment. One should have the letter L along side of it, that's the low side or idle side. The other of course would be the letter H which is the high side. That adjustment is only to be made when the unit is started and idling. When you give it full throttle that's when you adjust the H screw. Factory settings are usually 1 1/4 turns out from dead stop on the L screw and approx 3/4 to 1 turn on the H screw after unit is running. If however, this doesn't solve the problem a simple carb kit can be purchased for about 5 bucks and very easy to install. Good luck.

It sounds like the float is sticking in the carb. Since the carb is higher than the fuel tank it pulls the fuel in by vaccum of the engine. when running at high rpms, it can burn the fuel thats flowing into the carb, when you idle down, the bowl of the carb is filling up with fuel faster than the engine can burn it and causing it to flood. Then when it shuts off at idle it does not want to start back up because it is flooded. To make a long stary short, pull the carb and give it a good cleaning and your problems should be solved.

can be your plue