Mercruiser fuel inject 377

[Mjsearay]

Hello, new here!
Just purchased a Sea Ray with rebuilt 2009 engine. Half tank of fresh gas. It’s making a loud clanging/ hammer noise at mid range speeds, only under load. Does not do it in choke or neutral. Doesn’t do it at top end. Plugs are all good. Someone said it could be a sensor, cap and rotor, wires. Engine only has 8 hours on it. I’m in the Cape area, MA.
Can’t get the video of noise to upload. Thank you in advance!!

 

[Dieter]

Hello, new here!
Just purchased a Sea Ray with rebuilt 2009 engine. Half tank of fresh gas. It’s making a loud clanging/ hammer noise at mid range speeds, only under load. Does not do it in choke or neutral. Doesn’t do it at top end. Plugs are all good. Someone said it could be a sensor, cap and rotor, wires. Engine only has 8 hours on it. I’m in the Cape area, MA.
Can’t get the video of noise to upload. Thank you in advance!!

Would think that is detonation from running lean. What do spark plugs look like? You mention choke but also mention fuel injected, what is the engine or serial number? Would start with emptying the fuel filter and looking for contamination.