Mercury 40hp 1999 tiller handle

by Chris
(Plattenville, LA)

A good friend of mine let me borrow his boat with a 1999 Mercury 40hp tiller handle a few weeks ago and told me to run it because he barely runs it anymore. Well after I ran it a few times I had to start changing fuel lines because they were all dry rotted. After a few trail and errors I ended up rebuilding the fuel pump and cleaned the carbs. I ran it in a bayou for a good while with no issues, turned around and headed back to the launch and it started acting up on me. It would rev up and bog down like it would get a burst of fuel and then starve for fuel. The fuel tank is aluminum and I haven't drained it yet but I siphoned some gas out and i didn't see trash, I haven't changed the main fuel line or spark plugs yet either. Has anybody had this issue before and can help me solve this issue? Thanks in advance.