Honda 10hp bl100 green oil light only at idle

[Jeepsarebuilt]

Hello, i have recently acqired a honda 10 hp 4 stroke outboard model bl100 thats aproximally a 1985 motor. While test running it on my stand in water the green oil light is well visable at idle. When reving the motor up in neutral, the light quickly dims and goes out. Then slowing back to idle it comes back on. Is this a problem ? The PO claimed he recently changed the oil. I want to change it again, but where is the oil filter ?

 

[Jeepsarebuilt]

Re: Honda 10hp bl100 green oil light only at idle

Also wondering what kind of oil pressure is normal for this motor ? At idle and higher rpm ? Can i hook up a pressure gauge ?