Looking for suggestions
95 Merc 200 mounted on Bumble Bee 21' Pro Vee.Typically 53-54 mph maxxed out. Recently there have been variations in the the top speed. When I first hit the water 45-48 and decreases down to 40 or so.. if i back out of the accelerator then mash it again / sounds like its bogging down....then fish for awhile... fire it up it runs like normal / 53-54 mph.. next run it may revert back to abnormal or normal.
I have pulled the fuel tank intake / screen is clean, replaced the spark plugs last week..
Fuel filter and fuel lines were replaced less than 20 hours ago.
My novice possibly thoughts are injector(S), ECU or coil pack(s)
Any suggestions are appreciated

Sounds like your losing fire on one or two cylinders I would suspect a switchbox if you are losing fire one or more on one bank would be switchbox if you are losing fire on two one on each bank would be trigger.....OPTI

We can check your motor out.

I think I have tracked down the issue after I noticed I have used a gallon of 2 cycle oil in less than a few hours of running.Could the oil injection pump be stuck in the open position? My thought for testing is to simply premix a tank of gas and try it out.
Will it cause any damage to any of the systems if I simply plug the oil injection supply line from the tank to cut off the oil supply during the test on the lake?