Pre-ignition detonation/knocking

[fishing111]

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[Noelm]

I read it before and was thinking about it, I wonder if the plugs being loose were actually moving in the thread causing the noise?

[fishing111]

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[gazza2006au]

Do u have digital timing or mechanical timing? mechanical timing u have to set the advance spark at full throttle that is how i done my Mariner on the trailer but it is a old engine

[fishing111]

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[gazza2006au]

fishing it could just be a normal knock from the engine idling to low of a rpm