How to calm my rough running 8 hp 4 stroke

[jetsled]

I have a 2006 8 hp 4 stroke. Starts fine, accelerates fine, powers fine, recently changed plugs and oil (upper and lower) but tends to run rough at that special sweet spot speed I need for trolling.

What are the important maintenance level tasks I can perform to get the smooth performance back.

[smith46]

I think you can get the maintenance tasts in the owner's manual.Just check it if its given.