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美国华人, 帆船
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2,528 Posts
Discussion Starter #1
Yanmar engine 125 HP with heavy smoke, burn oil and no power under load, it is unlikely due to

1. Engine problem or
2. Marxprop malfunctioning.

What is your take on this?
 

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1,106 Posts
Is the prop and hull clean? The smoke and loss of power could be due to this. Loss of oil is another issue. Is there any oil in the bilge or visible oil leaks on the engine? Blue exhaust smoke is usually from burning engine oil.
 

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Corsair 24
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4,594 Posts
engine
 

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Corsair 24
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yeah more details, if it were prop youd be getting wierd vibrations and the like

it can also be tranny issues but power loss and smoke(what color) indicates engine issues...fuel delivery, compression, head gasket etc...

when you say no power under load do you mean a loss of power or it wont rev up simply put it has no topend?
 

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美国华人, 帆船
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2,528 Posts
Discussion Starter #6
More info as requested.

1. Prop and hull are clean
2. No oil leak
3. No blue smoke
4. Black Smoke and smell bad
5 Underload, engine will not rev high
 

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Closet Powerboater
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3,925 Posts
More info as requested.

1. Prop and hull are clean
2. No oil leak
3. No blue smoke
4. Black Smoke and smell bad
5 Underload, engine will not rev high

Sounds like the prop is too big, or the pitch is too much, or both.

What's the boat, prop, motor HP, age of motor and pitch?

MedSailor
 

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美国华人, 帆船
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2,528 Posts
Discussion Starter #8
It is Perry 59, it has the same prop since new from 2006. I am not sure when it was serviced, but I can find out. The Yanmar engine is a 125 HP diesel. Engine blew the head gasket a few years back by the delivery captain and subsequently repaired.

I spoke to the well established Bay Shore Diesel Marine in Annapolis. The mechanic there wants us to haul the boat out first. His reasoning made sense. But I thought I would do my due diligence in here.
 

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美国华人, 帆船
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Discussion Starter #10
Yes, Yanmar model #4JH3-DTE
 

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If the turbo is not running, the engine will be considerably short on power and if the injection system is not computer controlled, the engine will be running very rich accounting for the black smoke.

But then, what does a 'possum know about engines?
 

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Closet Powerboater
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Why haul the boat to work on the engine? Seems easier to test run it if it's in the water....

MedSailor
 

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Sounds like a turbo problem. Check that the hoses are secure and not leaking, as well as the wastegate is not partially open or opening before getting to the correct boost pressure..
 

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美国华人, 帆船
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2,528 Posts
Discussion Starter #14
That was my original request to test the engine first. Perhaps do the compression test and test the injectors. I agree that tt is far cheaper than haul out the boat. But the mechanic was so confident it was MaxProp problems.
 

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Old Guy
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Gee whiz, if it's the original setup, and it used to run fine, what kind of Maxprop issues does he think it is? If one of the blades isn't feathering completely I'd expect you'd sure know it via hellacious vibrations when in gear. Maybe send a diver down first for a look see? Unless there's other stuff you've been wanting to do with the boat out of the water...
 

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That was my original request to test the engine first. Perhaps do the compression test and test the injectors. I agree that tt is far cheaper than haul out the boat. But the mechanic was so confident it was MaxProp problems.
Unless the mechanic is sufficiently "confident" that he'd be willing to reimburse the cost of a short haul if it turns out the Max-Prop is fine, I'd seek a second opinion...

He's getting paid for his time anyway, I'd have serious reservations about enlisting the services of any mechanic who wouldn't want to take a quick trip out into open water first, and observe first hand the symptoms you're described... Hell, even running the boat in gear at the dock, under load, should be able to closely replicate the problem, no? Has this guy even HEARD the engine run yet?

Someone's gotta ask, sooner or later... Doesn't the actual CAPTAIN on this $1+ million boat have any clue how to proceed with this sort of deal?

:)
 

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Gee whiz, if it's the original setup, and it used to run fine, what kind of Maxprop issues does he think it is? If one of the blades isn't feathering completely I'd expect you'd sure know it via hellacious vibrations when in gear. Maybe send a diver down first for a look see? Unless there's other stuff you've been wanting to do with the boat out of the water...
It's hard to believe the MaxProp blades are not operating synchronously, given the way it is constructed (bulletproof gearing). If there was mechanical interference with the prop, there might be differences among the blades (e.g., bends, tears). I had snagged a cinder block about 10 years ago with my MaxProp and all three blades were dog-eared and torn. Sent it to PYI to have it remanufactured. Even with this damage, I was able to motor to a marina.

IMOH, the black smoke indicates something other than the prop.
 

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Corsair 24
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its already blown a head gasket right? look there first black smoke can be low compression and when under load its excarcebated more...

can you hear a knock?

like others say check the boost on the turbo or if its even working
 

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After catching a chunk of wood in my maxi (destroyed the hub)Blades OK but dead in the water. (no vibration) I put on my spare maxi (replaced mainly because of electrolysis ) Worked good to finish the charter season but then decided all on its own to change pitch to nearly nada. No vibration ,just no grip. Could a maxi change to too maximum pitch and just fan the water at great effort.?
 

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Closet Powerboater
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3,925 Posts
If the max prop blades were fubar wouldn't there be horrendous vibration?

I know nothing about turbos, but I gotta say, it sounds like a turbo issue.



Tom
 
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