50 hp mercury bogging down

drewmaxwell27

Recruit
Joined
Mar 15, 2010
Messages
4
my 2000 model 50 hp mercury is bogging down when at full throttle. it cranks and idles fine. put in gear, it runs fine at idle speed. once i go to take off, it starts bogging down and won't get above 2800 rpm. it did this last week, so i drained the carbs and it ran fine. its now doing it again. i've drained the carbs 3 more times and it's still running the same. any suggestions of what this might be?
 

crem1

Petty Officer 1st Class
Joined
Aug 30, 2005
Messages
365
Re: 50 hp mercury bogging down

The carbs might need thorough cleaning, immerse the unit in solvent and let sit for a day.
 

drewmaxwell27

Recruit
Joined
Mar 15, 2010
Messages
4
Re: 50 hp mercury bogging down

ok. thanks. well, i've been told that it could be anything from clogged high-speed jet to a coil or power pack. being that draining the carbs last week fixed the problem, i was thinking that it was fuel and not electric.
 

crem1

Petty Officer 1st Class
Joined
Aug 30, 2005
Messages
365
Re: 50 hp mercury bogging down

If you are getting fuel to the carbs then it's not a pump problem, unless you haven't replaced the pump diaphram in a long time
 

drewmaxwell27

Recruit
Joined
Mar 15, 2010
Messages
4
Re: 50 hp mercury bogging down

i only recently bought the boat. i'm not sure what all the previous owner has replaced on it though. i just couldn't understand why draining the carbs would work once. that's why i was thinking that it could be a clogged jet.
 

DuckOfDeath

Seaman
Joined
Jun 18, 2006
Messages
70
Re: 50 hp mercury bogging down

You could get similar symptoms if it's not firing on one cylinder. Verify you're getting good spark on all cylinders while it's acting up.
 

Sean-Nos

Petty Officer 1st Class
Joined
Jan 3, 2010
Messages
354
Re: 50 hp mercury bogging down

Have you checked the vent screw on your fuel tank.
 

bankermike

Seaman
Joined
Jan 31, 2006
Messages
70
Re: 50 hp mercury bogging down

Mr. Maxwell, have you checked the water level in your alternator? I knew a man that was having simular troubles and my Nephew suggested he check the water level in his alternator.
I'm pretty sure once the water level was properly adjusted the man's troubles were cured.
 

saumon

Lieutenant
Joined
Aug 2, 2004
Messages
1,452
Re: 50 hp mercury bogging down

Mr. Maxwell, have you checked the water level in your alternator? I knew a man that was having simular troubles and my Nephew suggested he check the water level in his alternator.
I'm pretty sure once the water level was properly adjusted the man's troubles were cured.

I've come across the muffler bearing before but it's the first time i heard about the alternator water level ;)
 

hamburgerman

Petty Officer 2nd Class
Joined
Apr 17, 2006
Messages
102
Re: 50 hp mercury bogging down

Sounds like he is getting water in the bowl thats why a draining worked for a bit (could be the muffler berings though)
 

bankermike

Seaman
Joined
Jan 31, 2006
Messages
70
Re: 50 hp mercury bogging down

Mr. Maxwell is the previously mentioned Nephew that suggested checking the alternator water level.
On a serious note, the motor does'nt spit, sputter or miss when not under a load. It runs fine on muffs. Only when in the water and under throttle does the moto bog down. I would think if the fuel/carbs had water in them the motor would have a miss or sputter.
 

drewmaxwell27

Recruit
Joined
Mar 15, 2010
Messages
4
Re: 50 hp mercury bogging down

i spoke with a mechanic who works on alot of mercury motors. he said its most likely the high speed jet clogged. thanks for all of the input guys.
 

Jeep Man

Commander
Joined
Oct 17, 2008
Messages
2,803
Re: 50 hp mercury bogging down

I've come across the muffler bearing before but it's the first time i heard about the alternator water level ;)

Don't throw an illogical answer into the problem, Saumon. You know a bad muffler bearing will cause a vibration, not bogging down. Most likely alternator water level or a torque frammick discombouble.
 

saumon

Lieutenant
Joined
Aug 2, 2004
Messages
1,452
Re: 50 hp mercury bogging down

Yeah, sorry for that. I've been told that the best way to avoid this kind of trouble is to fill your alternator with anti-freeze instead of water :)
 
Top