Stihl FS80 problem

[Dunn's]

Ok so the FS 80 is having a problem where you start it up with the choke on and everything is fine. Then you take the choke off and it shuts down within a few seconds.

Any ideas are appreciated.

[teebo95]

sound like you have a dirty jet and its leaning out when you take it off choke

[4.3mudder]

Sounds like the carb might be dirty, Take the needle out and and do a thorough cleaning. Might want to inspect gaskets for stiffness also. If all else checks out fine, it might need to be tuned a little bit. Has it sat up for a while not in use?

[Dunn's]

yeah it sat for most of 2008, I was going to take it apart tomorrow. If I have time.

Anyone know what the screw adjustments are supposed to be. I screwed them all the way in and the back them out 1 1/2 turns. When messing with it today.

[4.3mudder]

It should say on the orange housing right next to the holes. It might be around 1 to 1 1/4 turns out for both.

[topsites]

Could be as simple as the fuel filter needs replacing,
also it is possible a fuel line has cracked or corroded,
reason I say this is a choke-required-to-run situation
is usually a sign of a fuel shortage somewhere.

It might also need the adjustment screws re-set,
and I am assuming it does have fuel in it.

[4.3mudder]

and I am assuming it does have fuel in it.

LOL, I have kicked myself in the butt a couple times for that. :hammerhead::hammerhead:

[Dunn's]

Yeah I thought about the crack in the fuel line because that has happened with our backpacks before, new fuel line and they worked like new.

Haven't had time to look at the trimmer though because the onan generator that runs our versalift bucket is giving us problems.

i will let you all know what I find when I get a chance to look at it.

[1wezil]

Yeah I thought about the crack in the fuel line because that has happened with our backpacks before, new fuel line and they worked like new.

Haven't had time to look at the trimmer though because the onan generator that runs our versalift bucket is giving us problems.

i will let you all know what I find when I get a chance to look at it.

does the primer bulb move gas in the lines when you push on it ?

[RonAyersMotorsports]

First check fuel lines for breaks or cracks. Replace if needed. Replace fuel with new fuel. Prime unit. If unit doesn't prime easily don't bother rebuilding carb just replace. If unit primes well and fuel lines are ok. Turn L and H screws out 1 turn. Check these and get back to us. I'll then explain, if it runs, how to fine tune the carb settings. And like Topsites said replace the fuel filter as well.