Stihl FC55 strange problem

[Doug Hartman]

I picked up a Stihl FC55 edger (clean, low useage) to go along with my other Stihl equipment (chain saw, trimmer, tiller, blower) knowing it wouldn't start. It has good compression, good spark and gets fuel. Should be running. When I looked through the butterfly of the carb the fuel is just sitting there up against the side of the piston. I pulled the carb and cycled the edger but the piston never drops below the opening to let fuel in as if the connecting rod is too long. (The attached picture is as low as the piston will go). It goes high enough to see the bottom edge of the piston and the connecting rod. I can make most things run but this one isn't making sense. Is there something I'm missing?Thanks in advance!

 

[Tobystihl]

Fuel enters the cylinder via the crankcase, it's then forced up into the combustion chamber by the pistons downward stroke.

 

[Doug Hartman]

Thanks Tobystihl! Now knowing this, it's quite apparent I'm a 4 stroke guy. With have fuel, spark and compression, what prevents these from firing after they've been sitting?

 

[cscltd]

Timing could be off, exhaust screen plugged are couple of things that could be

 

[Doug Hartman]

SOLVED - Thanks cscltd! Clogged spark arrestor. Removed it and within a few pulls it was running great. Put it back in and it immediately died. Now to clean or replace. Thanks again!

 

[cscltd]

Excellent!
Can clean with propane torch and wire brush. Good as new

 

[StihlsawuserMS361]

Very common with that series engines for some reason. My 86 blower does the same also. Glad it was an easy fix Doug!