This is a dandy. A guy brings me his stock Stihl 064 power head and says, "It's not running quite right and seems loud. Please check it over." He leaves.
Next morning I removed the shroud and noticed a loose muffler, hanging on by a thread or two. From the front, the lower left bolt nearest the clutch side was missing, the lower right bolt was very loose, and so were the two short bolts at the top. The front casing of the muffler was somehow tight, but the muffler was loose from the cylinder. I removed those three outer bolts and the muffler fell off in my hand. Both bolts that hold the muffler to the cylinder were also missing completely and so was the exhaust gasket between the muffler and the cylinder. I bolted it all back together and replaced the three missing bolts and the missing gasket. Compression is good, and the engine started OK and runs fine.
The mystery question I have is where on earth did those two bolts that squeeze the gasket between the muffler and the cylinder go? How did they manage to come completely out and than drift into thin air? Through the exhaust port? Seems a bit small for an M5 x 16 bolt to get through and even if they did, wouldn't the operator notice the bolts exiting out?
Forum, please advise and discuss.
Next morning I removed the shroud and noticed a loose muffler, hanging on by a thread or two. From the front, the lower left bolt nearest the clutch side was missing, the lower right bolt was very loose, and so were the two short bolts at the top. The front casing of the muffler was somehow tight, but the muffler was loose from the cylinder. I removed those three outer bolts and the muffler fell off in my hand. Both bolts that hold the muffler to the cylinder were also missing completely and so was the exhaust gasket between the muffler and the cylinder. I bolted it all back together and replaced the three missing bolts and the missing gasket. Compression is good, and the engine started OK and runs fine.
The mystery question I have is where on earth did those two bolts that squeeze the gasket between the muffler and the cylinder go? How did they manage to come completely out and than drift into thin air? Through the exhaust port? Seems a bit small for an M5 x 16 bolt to get through and even if they did, wouldn't the operator notice the bolts exiting out?
Forum, please advise and discuss.