Stihl fs 350 with no L or H screws ?

[kirko]

Hi Gents,,
I have a fs 350 Brushcutter with a bit of a flat spot on first acceleration/spool up.I grabbed my trusty screw driver and was about to give the L screw a bit of a tweak when I noticed there wasn't one.I pulled the cowling off on the search for some tuning screws but all I could find were 2 circles printed on the carby with a l and h next to them but no holes or screws ? Does anyone have any clues or is the tuning of my carby in gods hands
Thanks in advance Kirk

 

[DND 9000]

Hi Kirk

You can`t tune that carburetor, because it has a fixed jet, so there are no H and L screws. You can only tune the idle speed with the LD screw.

 

[kirko]

Thanks DND 9000,,

First time I ve come across this on any of my stihl gear . My other 350 has H and L screws, I wonder if this one is an earlier model or something ?

 

[DND 9000]

Hi Kirk

Yes the early models had the fixed jet carb. The change to the carburetor with 3 adjusting screws is descriped in TI 9.2003 for the FS 350. But as I see at the moment in 1998 there was a carb with 3 adjusting screws, too.

Regards,
Sebastian

 

[CR888]

l'd get a tunable carb for it. But remember you can adjust the tune slightly by the amount of oil in your mix to an extent. More oil =leaner tune Less oil =richer tune. Not ideal l know but its a minor tool in your situation. l would run 50:1 in a fixed jet situation or whatever stihl specs. l don't mind fixed jet sometimes, but when they annoy you they do a good job of it.

 

[kirko]

Thanks CR888

I have 2 tunable spare parts carbs,, one off a fs 85 and one off an fs 110,, what are my chances of one of these fitting the 350 ? im guessing pretty slim,, might try when I get some spare time next,, if anyone can take the guess work out for me that would be great.
Thanks Kirk

 

[kirko]

Pinched the carb off my fs 120,,tunable,and the 350 is now cranking.
Put the fixed jet on my fs 120 and it is also running well,,Thought it might have inherited the flat spot but it didn't happen,,nice