Detonation.....

[Bryan Rose]

Not to sound stupid , but what does it sound like? I am familiar with what valves rattling and pinging sound like when a motor is put under load but is this the same thing as detonation. Once again what does it sound like?
Bryan

[Ken F]

What you are familiar with as "pinging" is detonation or "pre-detonation".
Probably one of the worst things that can happen to an engine.
Ken F

[FHI-prez]

Sound is a really bad way to determine whether or not pre-detonation is occurring. Your motor can be experiencing "pinging" with little or no audible warning. Consistent and often spark plug checks is a much better way.

[Bryan Rose]

Well I dont have it going on then..... I took the boat out today for the first time this season and had what seemed to be a low tone burping sort of sound. through the exhaust every now and then.... no power loss or engine cutting out but definately a new noise.... No effect on performance though..... ran like a scalded dog!
Maybe a gas issue but I put 3/4 new in the tanks and only had maybe 2 gallons from last season < Nov > in there. what d you think?
Bryan