PDA

View Full Version : Sthil FS90


blake101
06-04-2011, 11:24 PM
Okay Hard to start and will sometimes die at idle, do I need to adjust the valves, or look at the carb?

Ridin' Green
06-05-2011, 01:24 AM
Try adjusting the idle screw up a little bit. It probably has vibrated of its original setting to too low a speed.
Just follow the owners manual instructions, or go online to Stihl and check them there.

Grasman
06-05-2011, 02:33 AM
When the same thing happens to my 110's and 90's I adjust the valves and change the air filters.

MowHouston
06-05-2011, 08:17 AM
I agree with the air filter too. A lot of the time if I change the air filter it does wonders. Especially in this drought down here.

mictrik
06-30-2011, 06:54 AM
Check air filter. Have you been using a good synthetic oil like Stihl "Ultra"? If not, check the muffler & screen. You may want to look at the exhaust valve to see if it's excessively carbon-ed. Check spark gap, check valve clearance ( but this does not have to be done often). when it is running & you depress the throttle does it hesitate or respond quick? if it hesitates you may want to check the low speed needle & lean slightly. If it is excessively humid & the carb was adjusted in winter dry conditions this could be the case, though i doubt it.

blake101
06-30-2011, 01:23 PM
Check air filter. Have you been using a good synthetic oil like Stihl "Ultra"? If not, check the muffler & screen. You may want to look at the exhaust valve to see if it's excessively carbon-ed. Check spark gap, check valve clearance ( but this does not have to be done often). when it is running & you depress the throttle does it hesitate or respond quick? if it hesitates you may want to check the low speed needle & lean slightly. If it is excessively humid & the carb was adjusted in winter dry conditions this could be the case, though i doubt it.

Thanks for the information. It does hesitate a little, I will try the low speed needle.

blake101
07-15-2011, 12:56 PM
Okay Cranks great. When it is cold the throttle responds quick, but as soon as it warms up it will hesitate. Does any body have any solutions. I did adjust my valves and changed air filter and new spark plug. It just takes to long to rev-up.

alexschultz1
07-15-2011, 03:08 PM
check the muffler and make sure its not clogged at the end, take the screen out and check it.. may be an issue with a magnito clearance. maybe.. its pretty rare for that to happen on 2 strokes.

ed2hess
07-15-2011, 03:15 PM
Okay Cranks great. When it is cold the throttle responds quick, but as soon as it warms up it will hesitate. Does any body have any solutions. I did adjust my valves and changed air filter and new spark plug. It just takes to long to rev-up.

Did you adjust the low speed needle? I assume you have one? If it starts good and accelerates after starting then you got enough gas. If it bogs after it warms up then shut down the low needle a little bit. I doubt that you have both a low and high needle......that is the advantage of units with those so you can tune for weather conditions.

finneylawns
07-15-2011, 07:06 PM
Check out this post.

I posted this about my issues starting my weedeater and edger.

I currently have them at my local Stihl dealer for service, being that they are under warranty. I will post their finding hopefully on Monday.

http://www.lawnsite.com/showthread.php?t=353814

blake101
07-17-2011, 06:30 PM
Did you adjust the low speed needle? I assume you have one? If it starts good and accelerates after starting then you got enough gas. If it bogs after it warms up then shut down the low needle a little bit. I doubt that you have both a low and high needle......that is the advantage of units with those so you can tune for weather conditions.

Have not tried the low speed needle, I will have to get my manual out to see which one it is. I will try that. Does any one else have any suggestions? I also checked the muffler screen to see if it was clogged with carbon, and it wasn't. I need help. It just takes to long to rev-up to speed.

Kingfish
07-17-2011, 07:33 PM
Have not tried the low speed needle, I will have to get my manual out to see which one it is. I will try that. Does any one else have any suggestions? I also checked the muffler screen to see if it was clogged with carbon, and it wasn't. I need help. It just takes to long to rev-up to speed.




Dirty clogged carb?

dboyd351
07-17-2011, 08:02 PM
Check out this post.

I posted this about my issues starting my weedeater and edger.

I currently have them at my local Stihl dealer for service, being that they are under warranty. I will post their finding hopefully on Monday.

http://www.lawnsite.com/showthread.php?t=353814

finneylawns,
You were given the following advice on the post you quoted:
"Take the carb off and remove the side of the carb away from the primer. There's an internal filter screen that regularly gets clogged with very fine dirt/dust.
Clean that out and you should be back to normal."

Did you try that? Did it work?

blake101
07-17-2011, 08:15 PM
finneylawns,
You were given the following advice on the post you quoted:
"Take the carb off and remove the side of the carb away from the primer. There's an internal filter screen that regularly gets clogged with very fine dirt/dust.
Clean that out and you should be back to normal."

Did you try that? Did it work?

Will try that and let you know how it works. Thank you