Logo
FULL SITE MENU

40 hp mercury

S

saltlife321

Contributing Member
"A friend of mine just bought

"A friend of mine just bought a 2004 mercury 40 elpto. The previous owner told him that two mechanics told him that the motor has a burnt cylinder. What exactly do they mean? Is it the cylinder wall,piston,and rings? What has to be done to fix this problem? The burnt cylinder was caused from oil pump failure. (So he says)....
uhoh.gif
Any info would be helpful. Thanks"
 
"Kinda just like it sounds - t

"Kinda just like it sounds - too much friction toasted one of the pistons. If it was related to an oil pump problem, probably all cylinders will be scored to some extent.

That usually means a total rebuild - hone/bore the cylinders, a new piston(s), rings, maybe bearings - lot's of work, plus gaskets and seals.

The average shop would charge about 2500 for the rebuild, if he's handy and gets the right manual, it can be done (mostly) at home for about 1000 bucks.

Plus of course, the initial problem needs to be definately tracked down and corrected."
 
You say you can do most of the

You say you can do most of the work from home but he should still have the block re-honed at a shop right?.. And the right manual.? Would the manual you can buy directly from mercury be the right one? Is it smart to bore all the cylinders to the same size?
 
"yes, still need the machine w

"yes, still need the machine work done at a shop - the average cost (at least around my way) is about 50 bucks a hole for either a bore or a hone.

If doing a total rebuild, then yes, a Merc service manual (about 85 bucks) would be best.

And myself, I kinda look at it like this. If you are chucking 100+ bucks for gaskets/seals, taking all the time to tear down the block and disassemble everything to get at a single piston, why not at least have any "good" cylinders honed out and at least put new rings on those pistons.

Why take the chance that it will chew an old ring next year and have to repeat the process.

After all, in the total cost of things, to hone two extra cylinders is about 100 bucks and two sets of rings would be a 2 sets of rings is maybe another hundred - so for 200 bucks just don't think it's NOT worth doing."
 
Back
Top