Mercruiser 454?
12-19-2005 | 08:54 AM
#1
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Mercruiser 454?
Used boat purchase imminent, Baja 370 ES. Mercruiser 454 420 HP version with 680 hours. When/what can I expect in terms of rebuild or maintenance in the near future? How many hours can I realistically expect to get out of these motors before rebuild and/or replacement? Also, any pros/cons you can share?
12-19-2005 | 09:49 AM
#4
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From: Beautiful Lake St. Clair,MI
Re: Mercruiser 454?
If the engines are running well, I would just keep an eye on them. I don't like to do compression checks on engines that are running good, because you always get a reading that you are not going to like. Then you start to worry! Maybe I like to keep myself in denial! The engines may have been very well maintained, and the previous owner ran them soft. However what ever you decide to do to one, I would do to the other.
Good Luck with your new boat.
Good Luck with your new boat.
12-19-2005 | 10:38 AM
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From: sint maarten
Re: Mercruiser 454?
well... as mentioned here, you never know... 900 miles of mine wouldn't be the same as someone elses... and , you might not realize that letting the thing sit around un run and unstarted for a long time is probably worse than the hours...but what you can do is this....
1) a leak down.... this will tell you the precise condition of the valves and rings.
2) take the valve covers off and look at the valve train and check the valve clearences.... this will give you a clue as to cam wear.
3) drain the oil and smell it and rub it between your fingers... if it smells good and feels like oil thats a plus. if it smells like fuel and is thin, then everything is worn out inside. if it smells like fish then something or in the process of failing inside.
4) look at the plugs... if they are clean and more white/ tan then brown/ black , then you are ok... and not if they are not
but frankly at a 1000 hours you need to be think a set of pistons, a cam and lifters and bearings and valve springs anyway...
much cheaper to do it now as a preventitive than when you are sinking because a rod went thru the pan and the bottom of the boat...
1) a leak down.... this will tell you the precise condition of the valves and rings.
2) take the valve covers off and look at the valve train and check the valve clearences.... this will give you a clue as to cam wear.
3) drain the oil and smell it and rub it between your fingers... if it smells good and feels like oil thats a plus. if it smells like fuel and is thin, then everything is worn out inside. if it smells like fish then something or in the process of failing inside.
4) look at the plugs... if they are clean and more white/ tan then brown/ black , then you are ok... and not if they are not
but frankly at a 1000 hours you need to be think a set of pistons, a cam and lifters and bearings and valve springs anyway...
much cheaper to do it now as a preventitive than when you are sinking because a rod went thru the pan and the bottom of the boat...
12-19-2005 | 10:40 AM
#6
Charter Member #1171
Joined: Feb 2001
Posts: 4,018
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From: Clearwater, FL
Re: Mercruiser 454?
I have a customer with just over 1000 hours on 502 MPI's in a 38 special !!!!!
Leaving some blowbye of the valve covers from the breathers but just keeps running !!!!!
He is in the run it till it breaks club !!!!!!!
Leaving some blowbye of the valve covers from the breathers but just keeps running !!!!!
He is in the run it till it breaks club !!!!!!!
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I want to live in a world where a chicken can cross the road and not have its motives questioned.
I want to live in a world where a chicken can cross the road and not have its motives questioned.
12-19-2005 | 03:01 PM
#8
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From: FORTLAUDERDALE, FLORIDA
Re: Mercruiser 454?
Originally Posted by stevesxm
well... as mentioned here, you never know... 900 miles of mine wouldn't be the same as someone elses... and , you might not realize that letting the thing sit around un run and unstarted for a long time is probably worse than the hours...but what you can do is this....
1) a leak down.... this will tell you the precise condition of the valves and rings.
2) take the valve covers off and look at the valve train and check the valve clearences.... this will give you a clue as to cam wear.
3) drain the oil and smell it and rub it between your fingers... if it smells good and feels like oil thats a plus. if it smells like fuel and is thin, then everything is worn out inside. if it smells like fish then something or in the process of failing inside.
4) look at the plugs... if they are clean and more white/ tan then brown/ black , then you are ok... and not if they are not
but frankly at a 1000 hours you need to be think a set of pistons, a cam and lifters and bearings and valve springs anyway...
much cheaper to do it now as a preventitive than when you are sinking because a rod went thru the pan and the bottom of the boat...
1) a leak down.... this will tell you the precise condition of the valves and rings.
2) take the valve covers off and look at the valve train and check the valve clearences.... this will give you a clue as to cam wear.
3) drain the oil and smell it and rub it between your fingers... if it smells good and feels like oil thats a plus. if it smells like fuel and is thin, then everything is worn out inside. if it smells like fish then something or in the process of failing inside.
4) look at the plugs... if they are clean and more white/ tan then brown/ black , then you are ok... and not if they are not
but frankly at a 1000 hours you need to be think a set of pistons, a cam and lifters and bearings and valve springs anyway...
much cheaper to do it now as a preventitive than when you are sinking because a rod went thru the pan and the bottom of the boat...
12-19-2005 | 03:19 PM
#9
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Re: Mercruiser 454?
It's all in how you run them. The 454's in my dad's Chris Craft probably have 1500 hours on them. They're starting to get tired but they still start and run fine. That's a cruiser though, not much WOT on those.
