OK so here's the story. I bought a repairable boat this spring. I did a good job of repairing the damaged transom and outfitting the boat for my needs. When I bought the boat it did not have a motor so I found a 1999 mercury optimax 150 that had a new factory powerhead installed by a mercury certified tech and only 30 hours on the rebuild. First time on the water everything ran awesome. The motor fired off immediately. It ran at 5000 - 5200 rpm and hit just under 40 mph which was exactly what I was expecting. After that I took it to my mercury dealer so they could give it a once over. They gave it a clean bill of health. The next time I took it out (3 days after receiving the thumbs up from the dealer). It would not start. It would fire and immediately die. I was able to figure out that if I held the key in the start position after it fired and then slipped the shifter into gear before letting the key go, it would stay running. So I hauled it back to the dealer. They said it was the key switch and they replaced it. Everything ran fine the next few weeks, but then it blew the belt that runs the compressor and the alternator. So I hauled it back to the dealer. They replaced the belt and supposedly Lake tested it. My first trip out (again 4 days after the dealer gave me the thumbs up) it would not start. Its acting just like it did when the key switch went bad. I am able to get it started using the trick I described earlier, but now it won't power up. I am getting only 4400 rpm and running around 32 mph. I am going to replace the plugs and check compression and stuff like that tonight. Is there anything in particular that you guys suggest I check on my own before taking it back to the dealer again? Thanks
I did a bit of a tune up last weekend which involved changing the plugs. Two of the old plugs were black, the rest looked pretty good. After installing the new plugs it started right up and ran 100 percent better with the muffs than before. As I was running it, I had the air cleaner off the top of the engine and I noticed that the belt was vibrating like crazy (keep in mind that I just had in to the dealer 2 weeks prior for a blown belt and they charged me $350 to replace a pulley that they said was out of alignment). Long story short, I discovered that the tensioner spring had slipped a cog and was so loose that I could install and remove the belt with my bare hands. I am absolutely positive that it was like that when it went to the dealer to get fixed because that was the first thing I checked after the belt blew. Now my ranting is done, but I do have to wonder... Am I out of line to think that the mechanics should have caught a bad tensioner when there is a belt issue? Also, if they Lake tested it, wouldn't they have noticed that it was only pulling 4200 rpm and tried to upsell me on some more shop time or a different prop? I think I am going to find a new place to service my boat.