Ok guys, riddle me this. The last couple of trips my 1999 Merc 25 two stroke has been acting a little strange. I have a theory as to what’s going on with it, but want some other opinions before moving forward. So here’s the deal… Two trips ago I noticed that the motor would bog down a bit while accelerating. Basically it would idle great and run perfect at low RPM, but when I’d get to about half throttle it would hesitate, then struggle for a few seconds before suddenly getting a surge of power and continuing to accelerate smoothly up to the max RPM. Top end was great, with plenty of power and speed. The next trip, I added seafoam to the tank but the problem persisted, although it wasn’t quite as bad as the prior outing. This last trip the problem was worse than ever before. In fact, the mid-throttle bogging down actually stalled the motor a couple of times. I was able to work through it and salvage the trip by adjusting the fuel mixture. I tried various settings, but ultimately running the motor a half turn richer seemed to help more than anything. Again, it started, idled and ran at WOT perfectly, but half speed…forget about it! Now, I should add that before this last trip, I tried doing a deep seafoam treatment to the engine using the following procedure. “I also tried your suggestion on seafoaming my motor today, except I took it one step further. In addition to what you did, I pulled the fuel line off the filter on the carb side, ran the motor until it was dry, choked it and ran it a few seconds more til it was totally out of fuel in the carb. Then I stuck a funnel in the fuel line and poured the seafoam in. With plugs disconnected I then cranked the motor until all the seafoam was sucked in. Repeated that about 9 or 10 times, then used your straw method to pour seafoam into the air intake. Let that sit for about 3 hours, then started it up and burned all the seafoam out.” So what do you guys think?