Hi, sorry if this post is in the wrong place, I'm new.
I have a Stihl FS450 brushcutter which suddenly stopped one day like it had run out of fuel.
I checked fuel and filled it but it would 't start.
Next I checked for a spark. There was one, although it looked a little weak to me, certainly not like I've seen on the car. Still, since there was a spark, I continued to suspect a fuel problem.
I changed the in-tank filter, the fuel line from tank to carb, the air filter and the spark plug. No start.
I checked the coil and lead and got continuity through to the spark plug cap - although it's hard to know exactly what's going on inside the coil but I checked it from the small metal tag at the back which has a wire connected.
Back to fuelling and I rebuilt the carb with new parts, no start.
I changed the complete carb, no start.
Now back to the spark, maybe it was weak. I changed the coil and set the gap to the flywheel at 12 thou, still no start.
I removed and cleaned the little valve that helps starting in case it was stuck causing low compression, all seems fine there.
I'm now at a loss to understand what to do next. I can only think that the spark is weak for some reason and not strong enough to ignite the fuel mix.
I suspected a short in the cable that goes to the handle on/off switch but, if that was so, there would be no spark at all.
The piston moves freely. Could there be a problem with the flywheel magnet? Could it degrade to the point that the spark becomes weak? I wouldn't have thought so.
Any help will be most appreciated.
