Eric C 109 #1 Posted June 15, 2015 Since owning my 520 for about a year now with zero issues, I decided to pull the engine to clean it up, adjust the valves and change the oil. So I get the engine out and set it on a bucket. No problems so far. Pull the air cleaner housing and engine tins. Piece of cake. This thing is WAY OVERDUE for a good cleaning. The top of the engine and valve covers are just full of crud. On to the exhaust bolts, the front two come out with no problems. I move the crud from around the rear two bolts, but there is only one bolt. I think to myself, that's weird. On to the intake. Loosey 4 bolts, no problem. Then I pulled the intake manifold and took a look at the intake valve area on the rear and low and behold, a crusty and charred exhaust bolt!The sight of this immediately flashed back memories from 25 years ago.... FOD! For those of you that have never worked around aircraft, FOD stands for Foriegn Object Damage. I still cannot believe that bolt did not jam the intake valve. Feeling lucky. 6 Share this post Link to post Share on other sites
312Hydro 473 #2 Posted June 15, 2015 Amazing story! Glad it had a happy ending! Share this post Link to post Share on other sites
AMC RULES 36,940 #3 Posted June 15, 2015 Lucky you found it... gonna reuse that bolt? Share this post Link to post Share on other sites
stevebo-(Moderator) 8,034 #4 Posted June 15, 2015 I had a FOD on time on a Case 210 with kohler K series 10hp. I could not get this thing to run right. Messed with carb, points etc long story short I pulled the head to find one of the carb air cover panhead screws inside and was holding one of the valves open. You never know... 2 Share this post Link to post Share on other sites
Eric C 109 #5 Posted June 15, 2015 Lucky you found it... gonna reuse that bolt? Of course! 1 Share this post Link to post Share on other sites
Eric C 109 #6 Posted June 15, 2015 I can only speculate that the last person into this engine was in a big hurry to button it up and not go back looking for that bolt. Share this post Link to post Share on other sites
shallowwatersailor 3,213 #7 Posted June 15, 2015 Since owning my 520 for about a year now with zero issues, I decided to pull the engine to clean it up, adjust the valves and change the oil. So I get the engine out and set it on a bucket. No problems so far. Pull the air cleaner housing and engine tins. Piece of cake. This thing is WAY OVERDUE for a good cleaning. The top of the engine and valve covers are just full of crud. On to the exhaust bolts, the front two come out with no problems. I move the crud from around the rear two bolts, but there is only one bolt. I think to myself, that's weird. On to the intake. Loosey 4 bolts, no problem. Then I pulled the intake manifold and took a look at the intake valve area on the rear and low and behold, a crusty and charred exhaust bolt!The sight of this immediately flashed back memories from 25 years ago.... FOD! For those of you that have never worked around aircraft, FOD stands for Foriegn Object Damage. I still cannot believe that bolt did not jam the intake valve. Feeling lucky. Go buy a lottery ticket!!! 2 Share this post Link to post Share on other sites
mels 174 #8 Posted June 15, 2015 Or, "Debris" if you're policing up the flight line... Share this post Link to post Share on other sites
WNYPCRepair 1,875 #9 Posted June 15, 2015 Or, "Debris" if you're policing up the flight line... We still called it FOD on the flight line. Every morning, FOD walk. 1 Share this post Link to post Share on other sites
mels 174 #10 Posted June 15, 2015 Same here, was referring to debris vs. damage... 1 Share this post Link to post Share on other sites
WNYPCRepair 1,875 #11 Posted June 15, 2015 Yeah I always thought they had the terms wrong Share this post Link to post Share on other sites
Dennys502 244 #12 Posted June 15, 2015 Every mechanics nightmare - dropping something down the carb and not noticing it. Hard on pistons and valves.In the Air Force in Thailand we had a FOD cart which was a large go cart made on base at some time that we drove around picking up FOD. I had that job once as I was randomly selected to do it. Kind of fun to drive around the flight line all day. 1 Share this post Link to post Share on other sites
boomers_influence 106 #13 Posted June 16, 2015 ericthe bolt from the exhaust is to large topass through the intake valve.NOW. an air cleaner bolt is large enoughto hold the valve open.the choke and throttle shaft screws arethe ones that will do the damage to the piston and cylinder head.thank you. boomer ( the used onan engine parts guy,also NOS and new ) 1 Share this post Link to post Share on other sites
Eric C 109 #14 Posted June 16, 2015 Every mechanics nightmare - dropping something down the carb and not noticing it. Hard on pistons and valves.In the Air Force in Thailand we had a FOD cart which was a large go cart made on base at some time that we drove around picking up FOD. I had that job once as I was randomly selected to do it. Kind of fun to drive around the flight line all day. You Air Force guys are spoiled. I was lucky enough back in the day to be volunteered to pilot the FOD machine on the flight deck of the TR (CVN 71). The machine consisted of a heavy duty wet vac mounted on a flat bed cart like they have at Home Depot. I had to push that thing around and suck out the million or so tie down pad eyes. Share this post Link to post Share on other sites
WNYPCRepair 1,875 #15 Posted June 16, 2015 We were Marines. We walked and picked it all up by hand, LOL No money in the budget for machines 2 Share this post Link to post Share on other sites
Dennys502 244 #16 Posted June 16, 2015 The FOD cart was assembled from scavenged pieces from different departments. Steel welded together for a frame. This was back in 69 so I can't really remember exactly what it looked like. I just remember it was very crude - not something I would make but did the job. 1 Share this post Link to post Share on other sites
mels 174 #17 Posted June 16, 2015 We were Marines. We walked and picked it all up by hand, LOL No money in the budget for machines Sheeesh! At least you Marines had boots. We Army pukes walked the flight line barefoot 5 miles, uphill both ways! 2 Share this post Link to post Share on other sites
bmsgaffer 2,043 #18 Posted June 19, 2015 My onan thats up on the bench for repair is missing an exhaust bolt... Havent gotten the exhaust or intake off yet, but now i sure plan on it before running it again! Share this post Link to post Share on other sites
cheesegrader 433 #19 Posted June 29, 2015 The Air Force guys had to take off from the flightline patrolled by the Army guys, and HOPE they wouldn't be killed by sucking up:Empty whisky pintsBrass casingsMetal caps to said whisky bottlesCondoms (fresh and soiled)Condom wrappers.I have seen every item on the above list sucked into an engine. Makes you wonder what the Army guys were up to on those late night FOD patrols! Share this post Link to post Share on other sites
WH nut 553 #20 Posted July 4, 2015 The Air Force guys had to take off from the flightline patrolled by the Army guys, and HOPE they wouldn't be killed by sucking up:Empty whisky pintsBrass casingsMetal caps to said whisky bottlesCondoms (fresh and soiled)Condom wrappers.I have seen every item on the above list sucked into an engine. Makes you wonder what the Army guys were up to on those late night FOD patrols! Dont ask, dont tell lol As soon as I saw FOD, I knew you were Air Force. 32 years retired here. Share this post Link to post Share on other sites
