heelp desperate, 5 mecanics, nobody can help, excess of oil and fuel, engine wont run

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
i bought this boat with 2 outboards almost a year ago, one engine runs great, the other has been a pain since i bought it.
they are twin mercury 2007 efi 150xl

the problem with the bad engine is and has always been the same.
it starts right up, doesn't run very clean but it does run and idle.

as soon it runs under load for a few minutes the engine will shut off due to excess of fuel and oil.
to turn it back on ill have to leave the starter on for 10 seconds or more until it comes back up again, but then it starts smoking like crazy, wont idle properly and keeps going off.
all i do is trolling, so when i troll the engine runs and you can watch it get filled up with oil and gas within minutes until it shuts off.

the only time the engine does run properly is when completely accelerate the other working engine, then the bad engine does come up and runs good, this is only at full throttle.

i have changed all filters, spark plugs, both fuel pumps, water pump, gaskets and i have replaced the reed blocks with USED reed blocks.

there definitely seems to be a huge excess of unburned fuel, the spark plugs are also full of oil within minutes of cleaning.

also see attached pics of the oil sludge coming out of the prop after running

heeeeelllppp im desperate, nobody seems to be able to find the problem !

http://tinypic.com/r/263ec6x/8
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Take a fuel pump pressure reading on both motors.
Compare and swap.
See if it follows the regulator.
The regulator could be bad?

I had a 225 with the same or similar problem.
The first step in diagnosing said take a pressure reading.
Mine was off by 4-6 pounds.
I asked EVERYONE even the Mercury Gurus.
They all said the regulators NEVER go bad. So I spent a lot of $ and finally changed the regulator.
Problem solved.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
With such a challenging thread title, you should get plenty of folks trying to fix your engine problems. Some on here will certainly take it as a personal challenge to fix what five other pros couldn't... Clever ploy... :thumb:
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Bad regulator, injector/s flooding or mechanical fuel pump diaphragm busted/split
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
i forgot to add while trolling and the engine takes less and less rpm until shutting off, even giving it more throttle will not bring it back up to run.

what i have also noticed is if i till the bad engine up by some, the rpm improve again, but for complete revoery the engine must remain shut off, and after 30 min or so will run again for a few min until it fills up with oil and gas again.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
8,776
What have the five mechanics tried doing to solve the problem? Where they outboard marine technicians?
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
If the above suggestions don't help, the most common cause of electric fuel injection running rich is the temperature sensor. If it is stuck at cold, it will run OK when cold but get worse as it warms up.
Also check for fuel in the vent line on the vapor separator. It should be dry.
In case you need it here's a link to a service manual for your engines http://boatinfo.no/lib/mercury/manuals/150efi-175efi-200efi.html#/0
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
thanks for all the advise so far.

im in the dominican republic, good mechanics apparently are nowhere to be found.
i did go tru all reputable and recommended mechanics so far an now results

so far we have cleaned the injectors, not replaced
replaced spark plus (keep getting oily right away)
all filters have been replaced
the vaporizer pump has been replaced (expensive !!)
the fuel pump has been replaced
the reed blocks (not all) have been replaced with used reed blocks
water pump has been replaced
the gasket for the reed block assembly has been replaced
the inside oil tank has been replaced.

could it be the coils ?

what has gotten me thinking for a second is the thermostat, the engine didnt have it when i bought it and i put 2 new ones in it.
havent noticed a difference with or without them.

also what i have noted as well the "bad" engine has a lot of BUBBLES coming out of the muffler, about triple as much as the good engine, what could that be ?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
You check the fuel pump pressure?
Does that motor use more oil than the other?
Serial#
 
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