Carb Issue???

[odin]

We run a pair of Stihl FS90R trimmers at my part time gig. I've noticed that they often stall when I flip them over to trim edge. My guess is we've got carb issues, but really have no idea on where to start with these units.

What say ye?

 

[Nitehawk55]

Check the fuel hose and filter .
Does it start right up after stalling out ?
Does it rev up as it stalls out ?

 

[odin]

It just falls flat on its face, dead. One unit will start right up. The other takes a few pulls. I'll check the hose and filter situation.

 

[Nitehawk55]

Start there , also if it acts up after a certain amount of time the tank vent may be an issue too .
Diagnosing is baby steps , start looking for the obvious first .

 

[odin]

Thanks, Nitehawk.

 

[Nitehawk55]

From what you're describing I would really be suspect of the fuel hose , it's collapsing or has a split in it that opens when you flip the unit to another position .

 

[Mutley]

Hi, I had an FS85r do that. My issue turned out to be the on/off switch inside the throttle assembly was old & loose. It simply switched the unit off when I flipped it over. I installed another throttle assembly from my parts box & all fixed. It may not be your problem, but its worth checking. Good luck with it!