Model # E225FHLSIF New Water Pump Kit approx. 25 Hrs Ago

Engine will idle at 2-3 psi. This was verified by dash gauge and also with external gauge hooked directly to the water port. Once on plane pressure reaches close to 20 psi and slowly decends to around 5 psi at this point I shut it down pryor to the alarm going off. I can tell by performance and the soot that it is getting hot and the system is getting richer. It takes around 30-45 seconds for the pressure to drop all the way to 5 and does not drop below 5. After sitting for a few minutes and restarting problem starts over.

This occurred for the first time last weekend while fishing a tournament. 2 weeks pryor at another tournament had no problems 20-30 psi at WOT.

A little History: New power-head this year. Broke-in by the book! (seems like forever) When the break-in period was over initial WOT pressure was 15 psi max. and dropped off while turning. Evinrude reps said 15 was the absolute lowest allowable. The motor is as high as it can be raised. Even removed 2 bolts on the jack-plate. (This was approved by the jack-plate manufacturer) Having said that while breaking in the motor we lowered the engine a full 2 inches and water pressure never changed.

I decided since I was at the extreme end of the pressure spectrum some investigation was required. I removed the lower unit and inspected the pump. At this time it was only 10 hrs old. After inspecting the water intake and not being satisfied with the design I ported the water intake to allow for a smoother flow of water at high speeds. After reassembling the lower unit and testing I had increased the water pressure to 25 psi and that's what it had been running at for 2 months fishing twice a week. The extra water pressure allowed the engine to run cooler, allowing the fuel system to run leaner making more power. The temperature change was verified by laptop and diag. software. It has never ran that fast with 2 people, half tank fuel, and loaded with "stuff".

Any ideas what could cause the water pressure to slowly bleed down? I have disassembled the blow-off valve and did not see anything obvious (is there a way to test it?). I am probably going to install a new water pump kit and I am debating disassembling the mid section to inspect water passage components. Also should water be coming out from the seam between the lower unit and the mid section. I've also read about people sealing the bleed hole in the impeller housing. Does this do something special?

Any help would be greatly appreciated!