This was a fairly common cause of demise for many Tecumseh HH series engines as well..
I have one I bought for a spare ,a HH120 12HP one,and I was reluctant to take the cylinder head off it because I was told it had rum well,and it did have excellent compression..and finding a new head gasket locally is usually a big pain..
I'm glad I did remove the head though--I found the top of the piston and the cylinder head above it all dinged up with impressions of screw threads,it looked like Trilobite fossils...and the brass screw from the throttle butterfly was firmly imbedded in the cylinder head,above one of the valves,which fortunately wasn't damaged,nor was the lifter or camshaft..and the cylinder wall was perfect,not a scratch in it!..
I am not sure if the head is cracked where the screw got punched into it,it may be,but I have a spare head,so thats no big deal..
I guess they used brass screws for a reason,hopefully if one gets inhaled,it being softer metal,it may not cause extensive damage..but it can!..steel screws would guarantee some bad things will happen..best way to secure these screws is to mash the threads on the side opposite the screw head after installing them with a tiny chisel or punch,mushroom it enough so the screw cant come all the way out if it ever loosens..
I have one I bought for a spare ,a HH120 12HP one,and I was reluctant to take the cylinder head off it because I was told it had rum well,and it did have excellent compression..and finding a new head gasket locally is usually a big pain..
I'm glad I did remove the head though--I found the top of the piston and the cylinder head above it all dinged up with impressions of screw threads,it looked like Trilobite fossils...and the brass screw from the throttle butterfly was firmly imbedded in the cylinder head,above one of the valves,which fortunately wasn't damaged,nor was the lifter or camshaft..and the cylinder wall was perfect,not a scratch in it!..
I am not sure if the head is cracked where the screw got punched into it,it may be,but I have a spare head,so thats no big deal..
I guess they used brass screws for a reason,hopefully if one gets inhaled,it being softer metal,it may not cause extensive damage..but it can!..steel screws would guarantee some bad things will happen..best way to secure these screws is to mash the threads on the side opposite the screw head after installing them with a tiny chisel or punch,mushroom it enough so the screw cant come all the way out if it ever loosens..
