Help with a Stihl FS80r rebuild

[Robrote]

Being the tinker'r that I am, I decided to bring back to life an old Stihl FS80r trimmer. When I got it, it would barely run, so I bought a new carb and the condition did not change. So I went deep.

I replaced the crank seals, new piston, rings, fuel lines. I put it all together and I still can't get this thing to run. I manually primed the carb and she fired up but won't stay running long. I am using TruFuel, the muffler has no screen in it. Plenty of spark when I spin it. I'm at wits end. Obviously i have adjust the carb ad nausiam to get this thing to fire. What am I missing?

 

[ktoom]

Have u tried starting it without the muffler on it? Even though the screen may be off the muffler, you still may have some gas or w/e clogging the muffler. Had it happen with a br420 blower.

Have you vacuum and pressure tested the trimmer since the rebuild?

Intake manifold good?

Does the primer suck gas up?

Set both carb screws at one turn out from fully seated. Dont bother messing with them just yet.

How new is the carb?

When u replaced the fuel lines, did u replaced the fuel filter and fuel tank grommets?

These are pretty simple trimmers. Just re-trace your steps. If it has spark and is getting fuel, then it should fire or pop.

 

[backhoelover]

i just has a 80 come it cylinder looked perfect. rings was in spec. had only 90 psi. new cylinder piston. rebuild carb fuel lines and shes a beast

 

[backhoelover]

will it run if you put gas in plug hole?