When I run my Stihl FS-90, the trimmer head spins and it is revving pretty hard while idling. This seems to have started happening after I did a tune-up (spark plug, fuel filter, air filter). Not sure what could have made it happen, I thought maybe I accidentally turned the carb screw.
I have tried adjusting the idle screw, and turning it does at affect the idles RPMs at all. Kind of stumped right now.
That's weird.I have tried to adjust my FS70r ala "Steves Small Engine Saloon".I can't tell a difference by ear,so i turn both screws in til seated and then 1 1/4 turn out each.Seems to run strong but no idle problems though.Maybe check him out on YouTube.Can't hurt.
#3
StarTech
First make sure you adjust the valve clearances to .004".
Then make there a little slack in throttle cable at the carburetor. The idle speed adjustment is the LA screw. You do need a tach as you are looking for 2800 rpm idle and the clutch engages at 3700 rpm; unless the clutch spring is broken.
IF the limiter caps have been removed, the basic settings after lightly seating the H and L are
– Open the high speed screw H
3 1/2 turns counterclockwise.
– Open the low speed screw L
1 1/4 turns counterclockwise.
