Two 1988 Mercury/Mercruiser 25hp outboards lost power

Last summer I took the boat out for the first time and ran both mercury 25hp motors. I believe the gas was from the last fall. They ran fine for a few hours then bogged down. Now they wont run at more than 25% maybe. We cleaned out the filters and lines and still no change. We replaced the plugs and wires with no change. I dont have a lot of money to spend on the wrong parts. It was not my idea to use the old gas though. Does anyone have any suggestions please! Could it be the carbs? I did not clean those out and I do not think my father did either. Please could someone give me some ideas of the most probable issues. I do plan on cleaning the carbs out, will I need to get a kit? I am assuming I will not be able to reuse the gaskets. I do not know if they have ever been changed. Thank you in advance for any help guys! I didnt get out once last summer because of this!!!

Re: Two 1988 Mercury/Mercruiser 25hp outboards lost power

I would highly recommend cleaning out the carbs. It really isnt that hard of a job, as long as you have half a brain. And you could get a carb repair kit offline for about 50-100 bucks. And it will come with all the gaskets you will need. I would also recommend taking your boat to a local marine mechanic and have him check the compression and spark. If you can rule out compression/spark, it almost certainly is the fuel/lines.