bobmarkert
Well Known Member
My AeroSport IO-375 engine has 115 hours on it and I'm doing my first condition inspection. I bought a new borescope, and not sure if that was a good idea or not! The problem is I don't know what I'm looking at. Cylinders 1, 2 and 3, their pistons and valves all look the same. Number 4 piston looks different. Some sort of crusting,... Or worse yet layers of metal flaking off #4 piston. I sure would appreciate an education on what I'm looking at. That will determine if I'm going to have a good night sleep tonight or burn 8 gallons of stomach acid an hour!!!!!!!!........
The first two pictures are of #4 piston
Thank you in advance
Bob
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_59_56_Pro_zpsnrmr6yvk.jpg&hash=f98bf55915e1cfc6e0e2fcedd533b1ff)
#4 Piston
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_59_34_Pro_zpsdx6oigrt.jpg&hash=e4decd5e3e65d54a9d09c62d8be2adc8)
#4 Piston zoomed in
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_42_55_Pro_zpsfgbx6arr.jpg&hash=4c2e9fbaed7016e5e014ef097439073e)
Piston #1
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_43_09_Pro_zps6ba1dh9v.jpg&hash=86b9de85daa11039b43b79db3b272f83)
#1 piston edge. Looks scarry me
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_45_51_Pro_zps7o4xrpkm.jpg&hash=9d18c361e492ed31ae82561cf005e7e5)
#1 cylinder valve
The first two pictures are of #4 piston
Thank you in advance
Bob
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_59_56_Pro_zpsnrmr6yvk.jpg&hash=f98bf55915e1cfc6e0e2fcedd533b1ff)
#4 Piston
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_59_34_Pro_zpsdx6oigrt.jpg&hash=e4decd5e3e65d54a9d09c62d8be2adc8)
#4 Piston zoomed in
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_42_55_Pro_zpsfgbx6arr.jpg&hash=4c2e9fbaed7016e5e014ef097439073e)
Piston #1
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_43_09_Pro_zps6ba1dh9v.jpg&hash=86b9de85daa11039b43b79db3b272f83)
#1 piston edge. Looks scarry me
![](/community/proxy.php?image=http%3A%2F%2Fi821.photobucket.com%2Falbums%2Fzz136%2Fbobmarkert%2FWIN_20160428_15_45_51_Pro_zps7o4xrpkm.jpg&hash=9d18c361e492ed31ae82561cf005e7e5)
#1 cylinder valve
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