Stihl FS85 weedeater won't start. Carberator adjustment

Reply

  #1  
Old 10-01-09, 06:35 PM
bgentle's Avatar
Member
Thread Starter
Join Date: Oct 2006
Location: Alabama
Posts: 5
Stihl FS85 weedeater won't start. Carberator adjustment

I have a Stihl Pro FS85 weedeater that has been running fine for years. Now I can't get it to run over an idle. It chokes down when I pull the throttle. I changed the spark plug and attempted to adjust the carb. The carb adjustments do not match what the manual show. The manual shows three adjustment screws but the carb only has one! what's up with this? I have searched online and cannot find anything concerning this. Anyone have an idea?
 
Sponsored Links
  #2  
Old 10-01-09, 09:02 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
Not all trimmers of the same model have the exact same carbs on them. It sounds to me like you may have a blocked spark arrestor screen in the exhaust.
 
  #3  
Old 10-03-09, 08:43 PM
bgentle's Avatar
Member
Thread Starter
Join Date: Oct 2006
Location: Alabama
Posts: 5
Thanks for the info. How do you find out what carburetor it is? How do I get to the spark arrestor screen?
 
  #4  
Old 10-04-09, 12:03 AM
hopkinsr2's Avatar
Member
Join Date: Feb 2005
Location: canada
Posts: 1,561
You can get to the spark arrestor by removing the muffler..Carb spray cleaner & a tooth brush works well for cleaning these... I'm afraid you'll have to remove the carb to find out exactly what you have... If a Walbro,, Zama,, etc, go to there websites & download the service manual... Buy a carb kit & recondition the carb & if everything else is well,, You'll be good to go!!!
 
  #5  
Old 10-04-09, 03:53 AM
Member
Join Date: Oct 2005
Location: USA
Posts: 274
That is a great brand of trimmer. Probably one of the best. I think Cheese has it right. Clean that spark arrestor and replace or clean the plug and your probably good to go for a year. I do it once a year now that I have found how much better it makes them run.
Here is what I do. I pull the muffler and clean the screen with a brass wire brush. I then clean the muffler engine port of carbon with a small stick of wood,that way I wont damage the cylinder or piston. Wooden popsicle sticks work great for cleaning the port.
 
  #6  
Old 10-04-09, 06:23 AM
bgentle's Avatar
Member
Thread Starter
Join Date: Oct 2006
Location: Alabama
Posts: 5
Thanks, I have been reading some other information on the net that people are removing the screen completely. Is this ok to do? Also, I have adjusted on the one adjustment screw and now I don't know how it should be set initially. do I need to completley remove the muffler to clean it?
 
  #7  
Old 10-04-09, 10:35 AM
bgentle's Avatar
Member
Thread Starter
Join Date: Oct 2006
Location: Alabama
Posts: 5
please forgive me for asking about removing the muffler, you have already said to remove it. another senior moment!
 
  #8  
Old 10-04-09, 06:35 PM
bgentle's Avatar
Member
Thread Starter
Join Date: Oct 2006
Location: Alabama
Posts: 5
I got it fixed! I took the muffler off and cleaned it and took the carb apart and cleaned it, put it back together and it it fired up and ran like new. Thank all of you for your help. This is a great forum.Beer 4U2
Bruce
 

Last edited by bgentle; 10-04-09 at 06:37 PM. Reason: forgot that i cleaned muffler too
  #9  
Old 10-04-09, 09:24 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
Great! Glad you got it! Thanks for the update.
 
  #10  
Old 10-05-09, 05:39 AM
Member
Join Date: Oct 2009
Location: Pa.
Posts: 3
Might want to use high test gas from now on.
 
  #11  
Old 10-05-09, 11:50 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,818
I don't recommend it. Use non-ethanol fuel if you can.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes