540/27fastech
New member
Hi, Just got a problem I am having I got a 502mpi built to a 540 when I am idling my water temp gauge is showing 135* when i plane out and start running the temp starts to climb to 175*/180*. It has a 140* t-stat in it. I have had the sender checked along with the gauge both are fine. I have checked all hoses and coolers for blockage nothing found. Its got me stumped.. Also the port riser runs cooler that the starboard side? Also I have put a new raw water impeller in it. If anyone has ideas let me know. thanks everyone