Ok bought a used engine from a guy who said it was a good engine. Put it in the car this winter , started it up with the stock oil filter cover on it and just a loop in and out of the oil pan. 80 lbs oil pressure cold , checked compresion and I had 150 after about only 10 minutes of run time so I figured it was an ok engine. Took it out of the car , took the car all apart and put it back together. Installed a small setrab oil cooler from the oil pan with 8an lines , a remoted oil filter adaptor with a line to my filter, then from there to my larger setrab oil cooler and back to the oil filter adaptor. Finished the car up saturday afternoon all but the body, so I rolled it outside and started it up and only had 20lbs oil pressure. Ran it for about 10 minutes shut it off , did alot of thinking, and figured out that the oil lines on the remote oil filter adaptor were wrong , so I changed them to the rite way and started it back up and still only 20 lbs oil pressure. So next I changed the oil filter and still 20lbs oil pressure. So last night I took all the oil lines, coolers, remote oil filter adaptor off the engine. I looped in and out of the bottom of the oil pan w/ 8 an oil line and reinstalled stock yamaha oil filter cover w/ no filter back on and started the engine. 80 lbs oil pressure rite away. So then I hooked up the small setrab oil cooler to the oil pan and started the engine and had 80 lbs oil pressure. Next I removed the stock oil filter cover and installed one the remote oil filter adaptors and ran a 8 an line to the oil filter ( fram) and came rite back to the in side of the adaptor. Started the engine and only had 20lbs oil pressure. So I disconnected the lines to and from the oil filter and ran lines to and from the larger setrab oil cooler and started the engine and still only had 20 lbs oil pressure. Then I disconnected the oil cooler and just looped out of the oil filter adaptor and rite back in , started the engine and still only 20 lbs oil pressure. Removed the remote oil filter adaptor, re- installed the stock yamaha oil filter cover and the oil pressure went rite back to 80 lbs. What do think ??