Things to look for when buying an engine

[inter_elegance]

Guy i saw a really nice clean engine at I&S in penal but the only thing i didn't like was that when i pull the throttle and looked into the intake chamber i saw a little oil but the thing is all the engines i saw so far maybe 15 of them all had the same problem is this normal. please tell me what else to look for before i buy one.

[GAK Electrical]

It is normal for any engine to have that.

[1001]

its due to the hose from the tappit pan