Hi all,
The TKS carb is giving a mechanical clatter sound, not meant here is the normal suction sound from the TKS enrichment module at cold start proving extra fuel. The TKS module has been tested by me to be sure and is ok. During the last outage the engine was hot and stalled at low rpms, oil pressure dropped from 60 to 20 psi, for the first time. Pulled a plug, looks like the engine is running too rich. Next start days later I listened to the engine and heard the sound I am talking about for the first time. The sound is there when cold and hot and has a steady pattern and not changing, as far I can hear, when changing my rpms. The engine starts easily and quits immediately when shut down. Engine model 4312025US, S/N 1A085141, 350CID 260HP, year 2007.
My mechanic however does not think there is a mechanical engine issue, though my initial thoughts were a recently broken piston ring or worn piston rod bearing on the crankshaft. But, listening close by (engine surroundings) there is no local spot with knocking or clatter from rotating/linear moving parts, it only comes out of the carb like it is a speaker. That is why my mechanic is focused on the carb but I think it is really strange. We however pulled 2 very minor plastic pieces (1/10 fingernail) from one of the throttle plates during close inspection but that didn't change anything. Most likely the pieces are from the flame arrestor, though it doesn't show pieces have been broken off.
I added a movie clip. The sharp clatter sound here seems much stronger than in reality.
Again, note that the sound is coming directly out of the carb only like you listen to the belly of the beast, which perhaps, is not even far-fetched. Sound remains from cold to hot (175) at idle rpm and pressure steady at 60psi. Not tested in gear (to avoid the risk of further harm).
View attachment vlc-record-2023-08-12-22h46m17s-merc5_7_soundoutcarb.mp4-.mp4
Perhaps someone recognizes this and/or can direct me to the potential issue. Thanks for reading my long story and hope for your help.
Many thanks,
Martijn
The TKS carb is giving a mechanical clatter sound, not meant here is the normal suction sound from the TKS enrichment module at cold start proving extra fuel. The TKS module has been tested by me to be sure and is ok. During the last outage the engine was hot and stalled at low rpms, oil pressure dropped from 60 to 20 psi, for the first time. Pulled a plug, looks like the engine is running too rich. Next start days later I listened to the engine and heard the sound I am talking about for the first time. The sound is there when cold and hot and has a steady pattern and not changing, as far I can hear, when changing my rpms. The engine starts easily and quits immediately when shut down. Engine model 4312025US, S/N 1A085141, 350CID 260HP, year 2007.
My mechanic however does not think there is a mechanical engine issue, though my initial thoughts were a recently broken piston ring or worn piston rod bearing on the crankshaft. But, listening close by (engine surroundings) there is no local spot with knocking or clatter from rotating/linear moving parts, it only comes out of the carb like it is a speaker. That is why my mechanic is focused on the carb but I think it is really strange. We however pulled 2 very minor plastic pieces (1/10 fingernail) from one of the throttle plates during close inspection but that didn't change anything. Most likely the pieces are from the flame arrestor, though it doesn't show pieces have been broken off.
I added a movie clip. The sharp clatter sound here seems much stronger than in reality.
Again, note that the sound is coming directly out of the carb only like you listen to the belly of the beast, which perhaps, is not even far-fetched. Sound remains from cold to hot (175) at idle rpm and pressure steady at 60psi. Not tested in gear (to avoid the risk of further harm).
View attachment vlc-record-2023-08-12-22h46m17s-merc5_7_soundoutcarb.mp4-.mp4
Perhaps someone recognizes this and/or can direct me to the potential issue. Thanks for reading my long story and hope for your help.
Many thanks,
Martijn
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