Cut these from my boat which has a 2003 4.3 Mercruiser in it. The oil filter was only used for one season and maybe had 30 hours on it. It seemed to have a fair bit of fuel smell though. I’ve been running Rotella T4 15w40. This change it got the same oil but with a Fram Ultra this time. Really impressed with the tough guards lately though. Included it pics of the fuel filter. It has a few seasons on it. Pretty interesting as they call it a water separator as well but I don’t see anything like a screen or anything to do that. It’s also such a big can for a tiny little filter, the can is about 4” tall. The filter media is about an inch tall.
Fram TG3980 and Mercruiser 35-802893T
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The water separation happens inside the filter, water sits on the bottom and fuel on top where the media is.
Yea you’re right. It has a good 2” of space where the water can reside rather then getting sucked up as it is heavier then the fuel.
The boat has 255 hours on it. Oil is pretty black and fuel smelling. The filter held up really well considering. It has been burning oil it seems as well the last couple of intervals. It only gets used a few times a year. Sometimes it’s warmed up, sees wide open throttle to get to the desired fishing hole then shut off. Boat engines don’t have the easiest life. It can be at 5000 rpm for extended periods then shut off. Or idled while trolling. This engine is definitely in need of a tuneup.
The boat has 255 hours on it. Oil is pretty black and fuel smelling. The filter held up really well considering. It has been burning oil it seems as well the last couple of intervals. It only gets used a few times a year. Sometimes it’s warmed up, sees wide open throttle to get to the desired fishing hole then shut off. Boat engines don’t have the easiest life. It can be at 5000 rpm for extended periods then shut off. Or idled while trolling. This engine is definitely in need of a tuneup.
My 4.3 I/O will take the FL400 class filter, not sure if the Fram you use is that class or not. There were a couple different marine 4.3s, one with a balance shaft and one without so the filters may be different. Mine is "Volvo/Penta" but pretty sure the blocks are all the same minus the balance shaft/lack of.
If yours has a 4BBL carb it should be a Holley 600, those can be adjusted but I wouldn't be concerned about it being a tad rich. I've had good luck with the NGK TR55IX plugs in mine.
I cross referenced the filter I used and it comes up with a motorcraft fl402. I found this filter by cross referencing what was on it before. Which essentially is a normal gm 4.3 filter I believe. This thing needs a tune up. Thanks for the tips on the spark plugs! And a good carb overhaul I think as well wouldn’t hurt.
