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Mercruiser 8.1 375 hp compression test results?



 
 
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  #1  
Old June 1st 05, 02:23 PM
snor
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Default Mercruiser 8.1 375 hp compression test results?

I just had a boat surveyed and the 2002 engines have the following
compression test results with 570 hours. Port: 1-200 2-200 3-200 4-200
5-200 6-200 7-200 8-200. Starboard: 1-145 2-200 3-200 4-200 5-200 6-200
7-200 8-200.
The 145 on the starboard engine has me worried. The mechanic who did the
test says that it is within Mercruiser specs and is nothing to worry
about. I also spoke to another mechanic who said it is no problem but I
feel that being down 27% is not a good thing.
I would appreciate any input that you may have from your own knowledge
or experience.
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  #2  
Old June 1st 05, 04:54 PM
Netsock
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"snor" wrote in message
...
I just had a boat surveyed and the 2002 engines have the following
compression test results with 570 hours. Port: 1-200 2-200 3-200 4-200
5-200 6-200 7-200 8-200. Starboard: 1-145 2-200 3-200 4-200 5-200 6-200
7-200 8-200.
The 145 on the starboard engine has me worried. The mechanic who did the
test says that it is within Mercruiser specs and is nothing to worry
about. I also spoke to another mechanic who said it is no problem but I
feel that being down 27% is not a good thing.
I would appreciate any input that you may have from your own knowledge
or experience.



  #3  
Old June 1st 05, 05:01 PM
Netsock
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"snor" wrote in message
...
I just had a boat surveyed and the 2002 engines have the following
compression test results with 570 hours. Port: 1-200 2-200 3-200 4-200
5-200 6-200 7-200 8-200. Starboard: 1-145 2-200 3-200 4-200 5-200 6-200
7-200 8-200.
The 145 on the starboard engine has me worried. The mechanic who did the
test says that it is within Mercruiser specs and is nothing to worry
about. I also spoke to another mechanic who said it is no problem but I
feel that being down 27% is not a good thing.
I would appreciate any input that you may have from your own knowledge
or experience.


25% variance is acceptable, but with all the others so close (exactly the
same to be exact), it *might* be an issue, but remember, compression tests
are down at about 120 rpm. A far cry from its 2000-4200 rpm torque range.

If you don't have any other symptoms (idle rough, missing, vibration, ect.),
I wouldn't worry about it.

--
-Netsock

"It's just about going fast...that's all..."
http://home.columbus.rr.com/ckg/



  #4  
Old June 1st 05, 10:48 PM
Woodchuck
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55psi less than the other cylinders is NOT good. The standard variance
between cylinder is about 20 psi.


"snor" wrote in message
...
I just had a boat surveyed and the 2002 engines have the following
compression test results with 570 hours. Port: 1-200 2-200 3-200 4-200
5-200 6-200 7-200 8-200. Starboard: 1-145 2-200 3-200 4-200 5-200 6-200
7-200 8-200.
The 145 on the starboard engine has me worried. The mechanic who did the
test says that it is within Mercruiser specs and is nothing to worry
about. I also spoke to another mechanic who said it is no problem but I
feel that being down 27% is not a good thing.
I would appreciate any input that you may have from your own knowledge or
experience.



 




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