I have an Ingersoll Rand compressor from Tractor Supply approx. 3 years old. 5 HP , 60 gallon , Model SS-5
Suddenlu would not build more than 60 psi and would keep running with no gain.
Removed head and valve assembly to find blown out head gasket , between the two cylinders.They are a paper type gasket and very thin in that area.
I called tech support and described my problem . They gave me a local number to call to have the gaskets sent to me next day from the factory.
Installed the gaskets and torqued the head bolts to 15 psi then 27 psi as instructed by tech support. All is well for a cost of under 30.00
An interesting observation is that after 3 years of working flawlessly at a home workshop pace with almost every day use , the hone marks are still intact on the cylinder walls as you can see in the picture.