I have a 1987 Yamaha V6 Excel 225hp .I got it back in the water after winter. On take off the engine rpms fluctuate about 4 to 500 rpms until the boat gets on plane, then it runs smooth except for the occational cough about every 5 min but those are very minor almost unperceptable. New plugs, new fuel pumps, and I blew out the fuel lines, the filter looks clean and good as new so I haven't changed it <br /><br />Any sudgestions would be greatly appreaciated