"I have twin MArine Power 350 Efi engines. Last year when I ran the boat at 3200 to 3400 Rpms everything worked great. However, If I bumped the Rpms to 3800 to 4000 Rpms the Port Engine would loose power and the tach would jump while the temperature gauge would climb to around 210 degrees. Now this year both engines are having the same problem even at 2000 Rpms. I have changed both water pumps and changed both fuel filters. If you can help I would appreciate it"