I have a 90 hp Mercury outboard engine yr 2000 with less than 250 hrs on it. I take good cre of it and it has served me well. This year I stopped using it in July, filled the tank and did not use it til the end of August when I found it was running ruff. I thought perhaps it had some condensation even though I left the tank full. I brought it to my local marina to have it winterized and asked them to look it over after I describe the issue to them. They called me back and told me that it was bad gas and they would need to install a filter system that Mercury had to filter the gas plus the needed to rebuild my carbarators to the tune of $800 not including the filter system. I told them that I thought the bad gas issue was incorrect and a bunch of balony. They told me that this was a common problem and bad gas was prevelant through out Ontario and Quebec. They stated that Mercury told them this. So I called Mercury Canada and explained the issue to them only to be told the same thing. I was also told that if I should leave my boat sit for two weeks without running it I would have to insure I added gas stabilizer to the fuel. I asked if this ment that should I fail to do so that I would need to redo the carbarators each time to which there was no reply. Now I run a lot of gas powered stuff with some of it sitting for months to seasons and I have NEVER had a problem with them. This sounds more like a design issue that the Mercury Marine division has found and they are looking to place the blame else where while we, their customers, will bare the cost of repairs and they will come out ahead. So has anyone else had this problem? Is this the new scape goat for manufactures to redirect blame so they don't have to take ownership of their mistakes? Or is bad gas a real issue? Some one please let me know. I for one will never buy a Mercury product again they have lost my trust.