Evinrude 9.9, 4 stroke, vibration

[Swannie]

I have just bought this engine and find that it has more vibration than the 8hp 2 stroke that it has replaced. Is this normal, any suggestions?Swannie

[DJ]

Swannie, More than likely, yes.A four stroke only fires on every other revolution of the crankshaft. A 2-stroke fires on every revolution.The more cylinders a four stroke has, the smoother they get. Unless a balance shaft is incorporated, which your engine does not have.