oil presssure on perkins engine

[Dale2]

I am working on a 3 cylinder perkins diesel engine in a fordson tractor. I understand the same engine is used in some of the massy tractors that used the 144 or 152 cubic inch engine. My problem is. My engine had been setting for about 3 years and I wanted to put the tractor back in service. So I have it running and sounding very good but when the engine is warm the oil pressure light will blink constantly. I have installed a manual gauge and it is fact dropping oil pressure. After looking into the problem I have found the drop occurs at the time that the oil hole in the idler gear lines up with the oil hole in the spigot. I don't understand the open hole in the gear that all the oil is dumping thru. The oil pressure has to drop when the holes line up. I must be missing something or I have a nother problem some where. Please help me if anyone is familiar with this engine.
thanks
Dale

 

[Dieseltech]

Some Perkins three and four cylinder engines the rocker shaft could be rotated to have more or less oil flow to the rocker arms, if yours is adjustable too maybe it could be shut down some. Find an MF 65 diesel service book, if I recall it's shown in the head repair section. I'd put on a 0-50 PSI gauge on to see what you actually have.