amoutlawed

Hi guys, a littlle help would be much appreciated.

We are on our family vaction and have run into a little engine noise that I would like to figure out so we can use the boat if possible.

The motor is a 95 454 magnum efi and has 600 hours. Last time out I thought the boat was a little slow to get on plane but it was super hot and I was loaded down so I wasnt sure there was a problem. I did go ahead and service my fluids and new plugs before we left out on vacation. Boat starts and seems to run good and makes no noise while reving it out of gear. Runs good through the no wake zone but when you throttle it up to get on plane it starts making a knock or ping at around maybe 2500 rpm. I shut the motor down and checked to make sure all my plug wires were on, checked oil ect and tried to get on plane again and the same noise happens. I also think the exhaust smells rich. I doubt I can get a shop to look at it in time for us to salvage vacation but should I see if I can atleast get someone to scan it? Should I start with checking timing? I have a limited amount of tools with me so I have not checked a lot but thought I should get a stethascope or something to try and locate the noise while my wife drives the boat and maybe get a timing light and check timing. Should I be checking fuel pressure also? Where would you start?

Thanks

Tinkerer

Any chance you may have dropped a spark plug or two when you were installing them? If you did maybe the gap got closed causing a dead cylinder ( gassy exhaust smell ) When was the last time you ran a double dose of fuel system cleaner in the boat? Did you change the cap and rotor also? If you did maybe the plug wires got on the wrong terminal.

amoutlawed

Tinkerer, thank you for the response. The plug gaps should be good but checking them and the wires is a good idea. I did change the plugs from champion to ngk but I checked several cross reference charts to make sure I got the right plugs, also compared the plugs to make sure the length was right. I did not change the cap and rotor. I have not run anyitfuel system cleaner through it this year. When I changed water seperator I dumped it out in a glass jar and that fuel looked clean but I have done nothi g fuel system related other than that.

I was trying to drive the boat and listen for the sound at the same time and I also didnt keep it under load for a very long time in fears of creating damage so I habe not narrowed down the location of the noise but at first glance its possibly coming from the even numbered cyl side or possibly behindthe engine. I realize the engine has some hours on it but the rich condition makes me suspect fuel or ignition problem.