125 HP fails to rev up

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
14,276
For decades, Mercury, on its Inline Engines, had no removable Cylinder Head. Removal of the Water Jacket Cover on one of the older inlines, and you would see this. That changed on the V6s. Your Engine is like the 1st Gen, no Head, but might look a little different with the Jacket Cover off

img016.jpg
 

lgaytan

Petty Officer 1st Class
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Jul 15, 2015
Messages
227
For decades, Mercury, on its Inline Engines, had no removable Cylinder Head. Removal of the Water Jacket Cover on one of the older inlines, and you would see this. That changed on the V6s. Your Engine is like the 1st Gen, no Head, but might look a little different with the Jacket Cover off

View attachment 416614
Thanks for this pictures this clears my mind a little bit I guess it seems everything is casted together in iron or some material as that, this means this can withstand better over heating? The jacket cover still aluminum I guess.
 
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racerone

Supreme Mariner
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Dec 28, 2013
Messages
39,634
Why do you doubt this?-----There is no cylinder head that you can remove !!-----Pistons go into a blind hole from the other end.-----The block and the dome with the plugs are ALUMINUM.----Cast iron sleeves are inserted in the cylinders.
 

lgaytan

Petty Officer 1st Class
Joined
Jul 15, 2015
Messages
227
The only doubt I have is that by this leak the engine doesn't rev up as water is not getting into the pistons, but again seems feasible that water getting into the plug cables can cause bad or non spark. Just trying to understand the issue.
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
39,634
Water does not get near the piston from this leak!----Replace this gasket and test run.---Simple job.
 
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