Since I took my Merc out of storage for the fishing season, I have only had the chance to have it out on the lake twice. Both times, the engine has acted up on me.<br /><br />Basically, when the engine was cold it was a lot harder to start than it used to be. Then when I took it out for a run, it didn't seem to rev as high as it should at WOT, and the boat seemed to run slow. After a being at WOT for a while, I slowed the motor a bit, and it began running rough, missing and smoking. After this, it quickly stalled on me. <br /><br />It took quite a bit of effort to get it restarted, and when it did, it smoked, sputtered and wanted to stall (and it did stall a couple of times). When I got it to run, I opened up the throttle, and it seem to run fine at WOT. In fact, now it seem to rev up to it's max RPM, and it also ran normally at low speeds. <br /><br />It did this two me both times I had the boat out. After the initial rough running and stall, it was fine for the rest of the trip. It would start one easy pull after this, rev up to max RPM, and run as fast as it should.<br /><br />The only thing I can think of right now that might be causing it, is that I have some old fuel in the tank. I topped off the tank, but about 1/8 - 1/4 of the tank is old stuff. Could this be the problem? Any suggestions on what to look at? This engine ran near perfect last season. I have a new set of plugs I am going to install, but I don't want to put them in until this problem is solved.
