It's a homebuilt, so I'm listed as the manufacturer, and I wrote the POH based on some existing examples. It's still an approved document though, and the inspector checked it as part of the C of A issue.
Agrajag,
If your aircraft is a home built aircraft (Experimental Amateur Built) you do not have a C.of A. Even if it is the very old style AABA certificate, the document is still not a type certified C.of A.
Your "POH style" document is not "approved" by anybody except you, it is just part of the document package you submitted to get whatever certificate, on which you fly.
"Certificate of Airworthiness" and "approved" have very specific legal meanings in certification terms, they are not generic terms.
All that makes absolutely no difference to how you operate the engine, or operated it properly. The engine doesn't care what bit of paper enables the aeroplane, to which it is attached, to legally ( or otherwise) get in the air.
Tootle pip!!