Okay guys, I am back with another disaster story for you. While out just cutting away with my FC110 (which we swapped the cutting heads for a trimmer, then put a grass-cutting blade on it), it all of the sudden stops - no noise, nothing. It just slowly starts to spin down.
So I get back to the shop, and it seems the connecting rod broke at it's thinnest spot - the neck just before the piston pin. In 3 separate places the rotating connecting rod poked holes in both the cylinder and pan. The pin in the piston was also broken away from the piston, but peeking at the internal damage shows that it broke away second, there is nothing to indicate that the connecting rod broke away with the piston parts.
I have a question: what in the world can cause a connecting rod to break at the neck? I should disclose that a friend gave us this trimmer when it had 'valve problems' and wouldn't turn over. Turns out that the exhaust valve retainer broke: the valve fell and was impacted by the piston, which bent the valve. Although I expected damage to the piston, I saw nothing but a minor dent in the top surface. My best guess is that there may have been a micro-crack that meant that our days were numbered with that piston? Not sure.
Pictures to come. Carnage/trainwrecks are awesome. (Except when they cost you money and the repair parts can only come from dealers! :S )
-CM-NC
