Merc 4.3

H

havoc_squad

Senior Chief Petty Officer
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Mar 5, 2011
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738
I'm curious where the reason behind that question came from?

Friends, family, Youtube, Facebook, Twitter?

Was it someone who attempted to work on them but didn't know what they were doing or someone just frustrated because they got a bad hand dealt to them on a lemon boat.

I think iBoats forum is about due for one of those hotly debated boating topics, one good enough to get a box of popcorn out for reading the replies.

Like which inboard motor is the best
Is fuel stabilizer any good and which is the best
 
Lou C

Lou C

Supreme Mariner
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Nov 10, 2002
Messages
12,686
Well if you try to save money & buy a 15 year old boat that was neglected…not maintained not winterized etc then yes…
If maintained they can easily last 30 years or more.
 
Lou C

Lou C

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People have to remember an I/O is a slightly modified automotive engine & for marine use you have to deal with the differences/issues inherent in that. As in:
Not self draining you must winterize
Water cooled exhaust you must replace when needed
Single speed transmission you have to make sure engine is propped correctly to minimize load on the engine
High rpm use all the time means you don’t use low viscosity automotive oil, use straight weights (30,40) or Merc or similar 25/40 or 20/50.
 
P

poconojoe

Lieutenant Commander
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My 4.3 is fantastic. It runs great and only needed/needs normal maintenance, dist cap, rotor, ignition wires, plugs, oil, oil filter, fuel filter/water separator, etc.
I did have to replace the original ignition module under the distributor cap. It was a quick, easy job and cost about $40.
It's a 2003 with a 2 barrel carb.

4.3 is a very common engine both in boats and in the past in several GM trucks.

Like anything else....if you take care of it, it should last a long time. This includes boats too.
 
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poconojoe

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dubs283 said:
That is not the ignition module, it is the ignition sensor.

OP can get some good info from the stickies...........
Click to expand...
Good catch. I stand corrected. Ignition sensor.
Idk...I was thinking sensor, but I typed module. Must be CRS. Can't remember stuff. (G rated version)
There's no ignition module under the distributor cap.
My original sensor from the factory was an exposed printed circuit board. It was all corroded. The new one is completely sealed. Much better.
 
Q

QBhoy

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Long story short…anyone that suggests or tells you that engines like the 4.3 gm (or most other of the usual marine GM like 3.0, 5.0, 5.7 etc) just don’t have the first clue about it. The 4.3 engine is simply undeniably amongst the most successful, reliable test of time proven engine ever put in a boat. Period. These things haven’t been put in enormous numbers of boats over the last 4 decades, for no good reason.
Not to mention the cheap as can be cost of maintenance.
There is just no arguing with these things in terms of their sheer numerous numbers and success rates, in terms of the amount of them still around from more than a life time ago for most.
Anyone that tells you these things and others of the same dna are troublesome…just either doesn’t know what they are talking about, has no idea around basic maintenance and consumable parts, or just watches far too much rubbish on YouTube featuring equally as silly people talking rubbish.
 
Bondo

Bondo

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QBhoy said:
Long story short…anyone that suggests or tells you that engines like the 4.3 gm (or most other of the usual marine GM like 3.0, 5.0, 5.7 etc) just don’t have the first clue about it. The 4.3 engine is simply undeniably amongst the most successful, reliable test of time proven engine ever put in a boat. Period. These things haven’t been put in enormous numbers of boats over the last 4 decades, for no good reason.
Not to mention the cheap as can be cost of maintenance.
There is just no arguing with these things in terms of their sheer numerous numbers and success rates, in terms of the amount of them still around from more than a life time ago for most.
Anyone that tells you these things and others of the same dna are troublesome…just either doesn’t know what they are talking about, has no idea around basic maintenance and consumable parts, or just watches far too much rubbish on YouTube featuring equally as silly people talking rubbish.
Click to expand...
Ayuh,..... My 4.3LX has well over 2,000 hours, that I put on it, 'n when I pulled it to junk the boat a few weeks ago, it's still got over 130 psi compression on all 6 cylinders,.....

Most boat motors never die,..... they're Killed by their owners,...
 
P

poconojoe

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dubs283 said:
But the 4.3L is sooooooooo



Didn't you catch the OP question? Why is the GM 4.3L so terrible? Literally the worst engine ever created? Tell us......
Click to expand...
Huh?
Are you implying the 4.3 is terrible?

This was the OP question:
"Are Merc 4.3 inboards problematic?"
He didnt say they were terrible, he asked if they were problematic. Big difference.
 
Lou C

Lou C

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I think dubs was being facetious lol. Sometimes humor is lost in posting!
 
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