Rattle in Mercury 40EO

[Ditt]

I have a Mercury 40EO 2000 3 cyl. When running it seems that something is rattling near the top of the motor. In idle, there is no rattling. Is it normal? This is the only problem?
Thanks

 

[j_martin]

Re: Rattle in Mercury 40EO

Low octane, lean mix, timing advanced too far, wrong prop causing lugging. These can cause detonation. Sometimes this sounds like a rattle.

If that's what it is, it'll eventually burn down the motor. I'd have a pro look at it, or dig into it yourself to be sure it's right.

I,m fussy. I change props to pull water skiiers with a 150, just because the motor sounds happier with it.


hope it helps
John

 

[The-Machinist]

Re: Rattle in Mercury 40EO

does it have a rope start? I have a 40 mariner that was doing the same thing, turns out the nut had come loose on top of the rope starter.(that one got messy) some replacing and some welding, and now its one of my favorite motors.