merc 2 stroke, 40hp vs. 50hp

[Frank Mehaffey]

I have a 2001 merc 40hp, 3 cyl. outboard for my old boat, and recently saw the specs. for a 50hp 3 cyl. outboard. They are exactly the same!!!! Does anyone know what the differance in these 2 motors would be? Compression or carb capacity or whatever. Thanks

[Frank Mehaffey]

I have a 2001 merc 40hp, 3 cyl. outboard for my old boat, and recently saw the specs. for a 50hp 3 cyl. outboard. They are exactly the same!!!! Does anyone know what the differance in these 2 motors would be? Compression or carb capacity or whatever. Thanks

[Frank Mehaffey]

I have a 2001 merc 40hp, 3 cyl. outboard for my old boat, and recently saw the specs. for a 50hp 3 cyl. outboard. They are exactly the same!!!! Does anyone know what the differance in these 2 motors would be? Compression or carb capacity or whatever. Thanks

[Donn]

Frank:

Look at all the ranges of an outboard manufacturer's line, and you'll find a very few engine blocks sitting in different HP ratings. I've seen one maker who uses the same block on 9.9-18HP engines.

I'm not a motor-head, so I can't tell you how they do it, but I can tell you that it's likely that a good mechanic can get 50HP out of your 40.

[Donn]

Frank:

Look at all the ranges of an outboard manufacturer's line, and you'll find a very few engine blocks sitting in different HP ratings. I've seen one maker who uses the same block on 9.9-18HP engines.

I'm not a motor-head, so I can't tell you how they do it, but I can tell you that it's likely that a good mechanic can get 50HP out of your 40.

[Donn]

Frank:

Look at all the ranges of an outboard manufacturer's line, and you'll find a very few engine blocks sitting in different HP ratings. I've seen one maker who uses the same block on 9.9-18HP engines.

I'm not a motor-head, so I can't tell you how they do it, but I can tell you that it's likely that a good mechanic can get 50HP out of your 40.

[TomRobb]

On a 2-stroke it's bigger carb, higher compression, some changes in the porting - subtle stuff. Four-strokes are more obvious, in addition to the above, cam lift and overlap changes and the like.
Different states of tune from the same basic engine is an old story. It isn't the razzle-dazzle that one might think. It's a legitimate answer to different engineering/manufacturing goals.

[TomRobb]

On a 2-stroke it's bigger carb, higher compression, some changes in the porting - subtle stuff. Four-strokes are more obvious, in addition to the above, cam lift and overlap changes and the like.
Different states of tune from the same basic engine is an old story. It isn't the razzle-dazzle that one might think. It's a legitimate answer to different engineering/manufacturing goals.

[TomRobb]

On a 2-stroke it's bigger carb, higher compression, some changes in the porting - subtle stuff. Four-strokes are more obvious, in addition to the above, cam lift and overlap changes and the like.
Different states of tune from the same basic engine is an old story. It isn't the razzle-dazzle that one might think. It's a legitimate answer to different engineering/manufacturing goals.

[Frank Mehaffey]

I found a outboard motor site on the left coast, and posed the question to them, or it, or whatever. The reply was that it was the carburation and exhaust tuning. I wonder if the innards of a 40 could take a little tweaking, or if the 50 had heavier and stronger parts? I like the reliability of the 40, but since I turned 45, I have an uncontrolable urge to go just a little faster. My wife thinks I need to up the prozak.

[Frank Mehaffey]

I found a outboard motor site on the left coast, and posed the question to them, or it, or whatever. The reply was that it was the carburation and exhaust tuning. I wonder if the innards of a 40 could take a little tweaking, or if the 50 had heavier and stronger parts? I like the reliability of the 40, but since I turned 45, I have an uncontrolable urge to go just a little faster. My wife thinks I need to up the prozak.

[Frank Mehaffey]

I found a outboard motor site on the left coast, and posed the question to them, or it, or whatever. The reply was that it was the carburation and exhaust tuning. I wonder if the innards of a 40 could take a little tweaking, or if the 50 had heavier and stronger parts? I like the reliability of the 40, but since I turned 45, I have an uncontrolable urge to go just a little faster. My wife thinks I need to up the prozak.

[PugetSound]

It is possible to bump the HP on a 40hp up to 50 but it would probably involve tearing down the engine. In theory, I suppose you can do it with a change in carberation but it would take some fiddling or a fair amount of engine know-how. Bumping the displacement capacity of the 40hp is probably the most straightforward way to up the power but, like I said, that would involve tearing down the engine to change the stroke or compression or piston or head or ..... well you get the idea.

The thing you want to be looking at is how much power you really need to drive your boat at hull speed. Try these equations:

speed (mph) = 3.4 [engine hp/boat wt.(tons)]^1/2
('engine hp' is the hp used, not the maximum)

knots = 1.15 x (mph).

hull speed = 1.3 [waterline(ft.)]^1/2

[PugetSound]

It is possible to bump the HP on a 40hp up to 50 but it would probably involve tearing down the engine. In theory, I suppose you can do it with a change in carberation but it would take some fiddling or a fair amount of engine know-how. Bumping the displacement capacity of the 40hp is probably the most straightforward way to up the power but, like I said, that would involve tearing down the engine to change the stroke or compression or piston or head or ..... well you get the idea.

The thing you want to be looking at is how much power you really need to drive your boat at hull speed. Try these equations:

speed (mph) = 3.4 [engine hp/boat wt.(tons)]^1/2
('engine hp' is the hp used, not the maximum)

knots = 1.15 x (mph).

hull speed = 1.3 [waterline(ft.)]^1/2

[PugetSound]

It is possible to bump the HP on a 40hp up to 50 but it would probably involve tearing down the engine. In theory, I suppose you can do it with a change in carberation but it would take some fiddling or a fair amount of engine know-how. Bumping the displacement capacity of the 40hp is probably the most straightforward way to up the power but, like I said, that would involve tearing down the engine to change the stroke or compression or piston or head or ..... well you get the idea.

The thing you want to be looking at is how much power you really need to drive your boat at hull speed. Try these equations:

speed (mph) = 3.4 [engine hp/boat wt.(tons)]^1/2
('engine hp' is the hp used, not the maximum)

knots = 1.15 x (mph).

hull speed = 1.3 [waterline(ft.)]^1/2