Optimax 115 surging

[RomeroT]

Good morning to all. New to this site, but seems to be very helpful. I have read so much on the web and still feel like im getting nowhere. Anyway i have an Optimax 115 with approx 60 hrs on it. Motor cranks, idles, and runs great. As soon as she warms up i have a surging issue when i go over 4000 rpm's. It seems to run fine for the first 10 min at 4500 rpm's but after that she will not cross 4000 without surging. Any ideas? I checked compression 120 in all 3. Changed plugs. No alarms at anytime. Oil is full, bulb feels firm but hard to check by yourself on plain. Any pointers or insight would be greatly appreciated. Thanks in advance. 2009 Mercury Optimax 115 S/N 1B719309

[SilverFox579]

Good place to start without having a diagnostic check - FUEL LINES AND PERFORMANCE PROBLEMS

[Nova Kaw 650]

Change the fuel filter lately?
Did the 2009's have a recall on the coils as well?

[EuropeanAM]

A check of the BASICS may prove productive:

-Compression Test
-Spark Test (verify ONLY the correct plugs used: IZFR5J)
-Fuel Quality, Delivery, and AIR/FUEL PRESSURE TESTS *

* Test and record Air/Fuel Pressures for:
-Idle
-Under Acceleration
-5/10/15 seconds after engine shutdown.