I recently(4 months ago) bought a Merc 50 hp. It ran good for the most part up until about two weeks ago. We have been goin out every Sun., for the most part. It began to get harder to start. It would die when I put it in gear at idle. Sometimes if I left the warmup cracked a little, it would go ahead and run. Would not accept a lot of throttle. If it didnt die, I would have to ease in to it and, so far, it would eventually pick up and run. I took it to the shop, no charge, and had it back in a couple of days. They said, when asked what was wrong with it, that they had been covered up and couldnt really remember. It sat a couple of days until it was used again. It left the ramp fine. We shut down after about a mile and a half(about 4k rpm, full throttle) When we started to tube some, it started the hard to start, missing upon acceleration, etc again. Any ideas what it could be? Or what a guy could do on his own(dont know much about them) to avoid a trivial trip to the shop? 