Thanks for the video. Can I ask, what would cause these to be hard to start when warm? I have two, both bought new and if they sit for 15 minutes after using they'll take a good 10 pulls to restart Also, how would we set the Philips head idle screw in these? I notice the low adjustment seems to perform the same function
I've adjusted all three carb settings and it seems to be running properly now! Pretty sure it was the low speed screw causing most of the problems, I adjusted it slightly back from idling high, adjusted the actual Idle screw (Philips head screw) so it idles nicely and voila. Thanks again
@@machinesnmetal I’ll try that. I’m gonna play with the low end carburetor setting as well. It was running for like 20 minutes great today. But then the low idle made it shut down. But eventually it got progressively more unresponsive no matter what throttle I was giving it. I’ve never tuned up a grass trimmer so I’m hoping it’s just the carburetor settings The air and fuel filters look clean. And the fuel itself is mixed exactly as the bottle says it should be. So it’s gotta be the carb I saw a good video about the FS94R having a screen in the carb that needs to be cleaned periodically Here’s the link ua-cam.com/video/4SN89-x-M88/v-deo.html
First, thanks for the video. FYI: At 2:20 on the time line you mentioned the the screw on the top which is torx was for the low end adjustment. It is actually for taking any slack out of the cable to ensure that you get full throttle on your machine by allowing the carb arm to actually touch the throttle stop on the carb body at full speed. You may have to remove a couple of the covers to actually view the throttle action. When adjusted properly it will take any slack out of the trigger. The actual low speed stop is located on the bottom adjustment screw on the side of the carb. The screw on the right is for making low speed adjustments to ensure you get a smooth transition from slow speed to high speed.
I'm sorry I think you're wrong the fs94 has a barrel carburetor and the low idle adjustment screw is at the top in the hole that I show in the video and the high-speed adjustment screw is on the back side of the trimmer look up a parts diagram for that model and you will see that the screw locations I described in the video are correct perhaps you have an older version of this trimmer that does not run the barrel style carburetor
The low was set fine to begin with. It started and idled nicely. When you went to squeeze the throttle it would bog as the hi mix screw was out of adjustment.
I have one of these and my problem is that it doesn't stay running, at first I thought it was the carb and changed it and I still have the same problem, I changed the fuel filter, fuel lines and spark plug and still can't get it to stay running. Any suggestions?
Ive worked on thousands of these. A stock, untouched zama/stihl carb should almost never need adjusted. Only time ive ever had to was when i lived in denver and they ran too rich for elevation. Unless i just put a new carb on, it needs valve adjustment or diaphragm replaced 95% of the time. You are fixing the symptom, not the problem. The problem is something is causing fuel not to be delivered as efficiently. There is either too much air leaking where it shouldn't or fuel restricted. The mixture screws dont just turn themselves to randomly get out of adjustment.Valve lash would be first place to start with these motors. If valve isn't opening and closing is phase the a/f ratio will be wrong. The second thing would be to clean carb and replace diaphragm. Then and only then should adjustme it screws be messed with. 95% of the time they don't need to be.
Как проверить всё то , о чем вы написали ? Причину как найти. У меня тоже fs 94, zama карбюратор ни разу не трогал- проваливается на средних и высоких оборотах. Буду очень признателен.
You took the words out of my mouth, with the exception of valve adjustments. This is a 2 stroke machine. On a 4 mix, yes, I would add valve lash to the list of possible culprits.
So the L screw for the low idle is just 2 set the idle when it's idling? And the high would be for Bhai Idol? You didn't you didn't say anything about the low idle well as far as needing to adjust it
If your trimmer having issues starting or idling is when you adjust it. You adjust it similar to how he did the idle but you don't want the rev up to high. You want it where it idles smoothly and don't shake like a stripper at a club. Once you feel its shaking to much you turn it the opposite way til it smooths out.
I have a FS-80 string trimmer and I am unable to adjust the carb. I see the L H etched on the carb frame but no screws. Any ideas? If you can provide your email I can send you pictures of the carb.
I run a small lawn mowing business and I've got issue with my 3 year old fs94 r it's been in the shop every spring and now this fall it's having issues again. My first fs94 lasted 5 years without a single issue. What Stihl has built in the last 3 years is just junk.
@@machinesnmetal they said wasn’t nothing wrong with it. I’m so upset. If u can , I forgot to tell u something. After it gets hot is when it starts cutting out, and it don’t take but about 5 mins. I’m thinking coil.
Thank you Sr.!!
Problem FIXED!!!
You saved a fs94 from the dumpster.
Thank you again.💪👍
You are the mechanic now!
Thanks for posting this. I was having the same problem with my km94r and this solved it. FYI, it is a 4mm socket that fits perfectly.
Rip out that annoying spark screen in the exhaust and watch it Rev
I’m having the same issue with my fs94 I’ll try this if it doesn’t work I’ll throw it in the garbage can where it belong.
Great info thank you!
Good Info ordered my adj tool. Hope I have the same results, Stihl doesn't want to hear about any fuel warranty issues on my second $70.00 carburetor.
Best to run zero ethanol fuel, will usually keep things running right in the first place.
Do I have to mess with the low adjustment?
Only if it needs it
@@machinesnmetal what exactly is the low for? Just wanna make sure before I start messing with it
it sets the air/fuel mixture when the engine is at an idle.
@@machinesnmetal thanks ! 🙏🏼
Best trimmer ever made outside of the FS80
For those who know! 😎 FS 80 was one of my first Stihls
Sthil#1 , that's what I'm talking about sweet, Sthil understands
Thanks for the video. Can I ask, what would cause these to be hard to start when warm? I have two, both bought new and if they sit for 15 minutes after using they'll take a good 10 pulls to restart
Also, how would we set the Philips head idle screw in these? I notice the low adjustment seems to perform the same function
Sounds like they are flooding do they start any easier when you squeeze the trigger and pull after they are warmed up?
@@machinesnmetal Hey thanks so much man. Yes, they do seem to get started a bit quicker if I hold the trigger in
Sounds like they are running rich, is the air filter new? Have you adjusted the valves recently?
@@machinesnmetal One is brand new, the other has just always been this way.
I've adjusted all three carb settings and it seems to be running properly now! Pretty sure it was the low speed screw causing most of the problems, I adjusted it slightly back from idling high, adjusted the actual Idle screw (Philips head screw) so it idles nicely and voila. Thanks again
I did this today. It worked. Thanks.
I love to save money thanks for your video
Thank you for the video 👍
Can you share a link for that tool
I have the same Stihl trimmer. Mine will start, but overheats and powers down after about 5 or 10 minutes.
Could it also be a carburetor problem?
Could be. Did you try loosening the gas cap when it starts to do it's dance?
@@machinesnmetal I’ll try that.
I’m gonna play with the low end carburetor setting as well.
It was running for like 20 minutes great today. But then the low idle made it shut down. But eventually it got progressively more unresponsive no matter what throttle I was giving it.
I’ve never tuned up a grass trimmer so I’m hoping it’s just the carburetor settings
The air and fuel filters look clean. And the fuel itself is mixed exactly as the bottle says it should be.
So it’s gotta be the carb
I saw a good video about the FS94R having a screen in the carb that needs to be cleaned periodically
Here’s the link
ua-cam.com/video/4SN89-x-M88/v-deo.html
First, thanks for the video.
FYI: At 2:20 on the time line you mentioned the the screw on the top which is torx was for the low end adjustment. It is actually for taking any slack out of the cable to ensure that you get full throttle on your machine by allowing the carb arm to actually touch the throttle stop on the carb body at full speed. You may have to remove a couple of the covers to actually view the throttle action. When adjusted properly it will take any slack out of the trigger. The actual low speed stop is located on the bottom adjustment screw on the side of the carb. The screw on the right is for making low speed adjustments to ensure you get a smooth transition from slow speed to high speed.
I'm sorry I think you're wrong the fs94 has a barrel carburetor and the low idle adjustment screw is at the top in the hole that I show in the video and the high-speed adjustment screw is on the back side of the trimmer look up a parts diagram for that model and you will see that the screw locations I described in the video are correct perhaps you have an older version of this trimmer that does not run the barrel style carburetor
@@machinesnmetal Mine was a FS90R so you could be correct.
Why the high screw side? Don’t you leave that last for fine tuning?
The low was set fine to begin with. It started and idled nicely. When you went to squeeze the throttle it would bog as the hi mix screw was out of adjustment.
I have one of these and my problem is that it doesn't stay running, at first I thought it was the carb and changed it and I still have the same problem, I changed the fuel filter, fuel lines and spark plug and still can't get it to stay running. Any suggestions?
What compression does it make?
Ive worked on thousands of these. A stock, untouched zama/stihl carb should almost never need adjusted. Only time ive ever had to was when i lived in denver and they ran too rich for elevation. Unless i just put a new carb on, it needs valve adjustment or diaphragm replaced 95% of the time. You are fixing the symptom, not the problem. The problem is something is causing fuel not to be delivered as efficiently. There is either too much air leaking where it shouldn't or fuel restricted. The mixture screws dont just turn themselves to randomly get out of adjustment.Valve lash would be first place to start with these motors. If valve isn't opening and closing is phase the a/f ratio will be wrong. The second thing would be to clean carb and replace diaphragm. Then and only then should adjustme it screws be messed with. 95% of the time they don't need to be.
This video is about adjusting the carburetor.
Как проверить всё то , о чем вы написали ? Причину как найти. У меня тоже fs 94, zama карбюратор ни разу не трогал- проваливается на средних и высоких оборотах. Буду очень признателен.
You took the words out of my mouth, with the exception of valve adjustments. This is a 2 stroke machine. On a 4 mix, yes, I would add valve lash to the list of possible culprits.
But he's fixed thousands of these... You'd think hed know it didn't have valves. THOUSANDS
Just got my tool from eBay today. 7 bucks and 1 week later
Will running a whipper snipper hard for long periods over heat it?
Absolutely not. It will run cooler than if you start and stop it constantly.
Do u know if a bad ignition coil , besides not firing, will it make one not run right . A Sthil.
Absolutely. A bad coil would make any machine not run right.
So the L screw for the low idle is just 2 set the idle when it's idling? And the high would be for Bhai Idol? You didn't you didn't say anything about the low idle well as far as needing to adjust it
If your trimmer having issues starting or idling is when you adjust it. You adjust it similar to how he did the idle but you don't want the rev up to high. You want it where it idles smoothly and don't shake like a stripper at a club. Once you feel its shaking to much you turn it the opposite way til it smooths out.
Will this work on Stihl hl94k ?
Thank you much appreciated
Awesome video!!!
so mine, dose'nt idle for even a second before shutting off. Also today pretty much lost all power still turns the head just barley.
Is your throttle cable still connected? They can slip off quite easily.
is it full of fresh fuel?
machinesnmetal bad carb, had it replaced
I have a FS-80 string trimmer and I am unable to adjust the carb. I see the L H etched on the carb frame but no screws. Any ideas? If you can provide your email I can send you pictures of the carb.
Sure send pics: machinesnmetal@gmail.com
Do you have a link for the tool?
Amazon has a 10 piece carburetor adjustment tool set. $10. Worth it!
Thought it would blow up holding it that long while lean
4mix don't rev fast enough to blow up. There's so much oil steam in the case it's almost impossible
@@machinesnmetal good point
What did you search for on eBay to find the tool??
Came with a carb I bought on ebay
Spline adjustment tool
I run a small lawn mowing business and I've got issue with my 3 year old fs94 r it's been in the shop every spring and now this fall it's having issues again. My first fs94 lasted 5 years without a single issue. What Stihl has built in the last 3 years is just junk.
Yeah it's all junk these days. I hung onto my old Shindaiwa t230. Best machine ever made in my opinion.
Thanks master
what would cause this model to smoke badley and spit huge amount of oil if its not the fuel mix
oil plugged up exhaust/spark arrestor
@@machinesnmetal to follow up - it's a small metal screen that covers the exhaust. take it off.
Hey I have the same unit and my throttle linkage that goes into the carb is sticking. Any idea what I can do to fix it?
is it the cable or the carburetor that is sticky
HELP!!!!
The heads on my trimmers spins fast on half choke. How do I fix that?
turn off the choke
you didn't explain anything about having to adjust the L side
Owners manual
Thanks yuo!!! I’m like yuo. Video
👍
Thanks for the information but accurate measurements are important. Four and a half millimetres isn't a real measurement.
How about just a pinch?
A brand new Sthil . 1 week old
Take it back to the dealer. Warranty
@@machinesnmetal they said wasn’t nothing wrong with it. I’m so upset. If u can , I forgot to tell u something. After it gets hot is when it starts cutting out, and it don’t take but about 5 mins. I’m thinking coil.