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2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
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2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Anyone have experience with Mercury? My engine will start fine and after going out for a short time will bog down almost as if it is not getting gas. Mercury finally sent a tech out when the mechanic couldn't fix it. He rode around with me for several hours with his PC hooked to the motor and said "everything is running right where it should be"; right after he said that it bogged down. He did not have a clue why and started replacing parts. After essentially replacing everything (don't know why they did not give me a new powerhead), the problem seemed to disappear; well at least for the rest of last season. Now, it is happening again. Mercury said they have done all they are going to do for me which really ticks me off, so I am on my own with a motor that runs sometimes and out of nowhere starts boggging down...Any help out ther? Obviously, I'll never get another Mercury product again !
RE: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
yea; unfortunately, this is Mercury's boy out of the factory and they send who they want; really does not matter since they have washed their hands of the problem...the mechanic I use is excellent and he is baffled by it; he also thinks they should have given me a new powerhead as they probably spent more than that in travel and parts and install of the parts.........what to do??
RE: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
unless it was a fully dressed power head it probably would not solve the problem.sound's more like a fuel problem or an intermittent electrical problem
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
you said it was a 60 four stroke in a early post. Same engine but I would think you would know what hp it is. Tell us what kinda of boat your running this 50/60 four stroke on. Sounds a like a fuel issue. Have you tried a remote take. Also, I have seen a few mechanical fuel pumps stick when running high rpms's. When the engine bogs, what do you do? Dose it start back up and run, ???
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Shop for a competent tech. Factory techs are probably less knowledgeable that the techs that work on engines every day. I would look at the basics like fuel filters, line blockage, trash in the fuel tank.
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
never said 60hp; it is a 50hp running on a 20ft Princecraft Party barge with a remote tank; we have checked every aspect of fuel delivery(lines, tank, etc). When it bogs, I can go to low rpm (1000 -1800) and limp into dock; just cannot juice it back up to higher rpms or it starts bogging and coughing; Merc tech, master merc mechanic and another mechanic cannot figure it out; getting real frustrated, may just trade motor in.....
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Quote:
rilesjax - 2/3/2008 6:15 AM
never said 60hp; it is a 50hp running on a 20ft Princecraft Party barge with a remote tank; we have checked every aspect of fuel delivery(lines, tank, etc). When it bogs, I can go to low rpm (1000 -1800) and limp into dock; just cannot juice it back up to higher rpms or it starts bogging and coughing; Merc tech, master merc mechanic and another mechanic cannot figure it out; getting real frustrated, may just trade motor in.....
You say it run fines for a while then bogs. Do you let it sit for a day or so and it will run fine again then bogs after running for a while. When it bogs did you try squeezing the primer bulb?
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
don't need to let it sit a day; I can go back out an hour later and it may run up the lake for 15 minutes before it starts again; sometimes squeezing the bulb will get me going for 100 yards, but sometimes it does not....crazy, huh? I think there is an e-tec in my future, but trying to figure this out
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Quote:
rilesjax - 2/3/2008 6:42 AM
don't need to let it sit a day; I can go back out an hour later and it may run up the lake for 15 minutes before it starts again; sometimes squeezing the bulb will get me going for 100 yards, but sometimes it does not....crazy, huh? I think there is an e-tec in my future, but trying to figure this out
So if squeezing the primer bulb will get you going for 100 yards, then it is fuel related. New power head is not going to fix it. You need to find out if the mechanical fuel pump was changed. Either call your dealer or merc and demand a complete new mechanical fuel pump and have them add a complete VST just for peace of mind. Or go out and run the engiune until it bogs and remove the mechanical fuel pump, I bet you a $100 bucks the plunger is stuck at the top. Can you hit the rev limiter pretty easy, this may also cause an issue?
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
I had the same problem with a 25HP Big Foot 4S. Everytime the tech left the "bog down RPM range" moved. First it was idle, then 1800, finally WOT. I have a very good dealer (Russo Marine -- Boston), and they took it for the winter and fixed it. I think they replaced the carb, but I'm not sure. You may want to call them.
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
thanks; they replaced the mechanical fuel pump last season as a just in case along with everything else because I thought the same thing; logic says it is fuel related....I might go to the mech and have him test it again....don't know about hitting rev limiter--is that where I rev to max rpm and it should back off automatically?
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Thanks, Dave; Mine are fuel injected which probably just adds to the confusion of things; also, my understanding is that there are 2 fuel pumps, an electronic and a mechanical-----they supposedly tested and replaced/repaired both...... what to do
Re: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Quote:
rilesjax - 2/3/2008 7:07 AM
thanks; they replaced the mechanical fuel pump last season as a just in case along with everything else because I thought the same thing; logic says it is fuel related....I might go to the mech and have him test it again....don't know about hitting rev limiter--is that where I rev to max rpm and it should back off automatically?
RE: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
I knew one case like this on a 1974 50 Merc. 2 stroke of course. It had an oversized piston in it that would jam in the cylinder wall when it heated up. Let it cool a while and it would run again and bog down again.
RE: 2005 Mercury 50 HP Four Stroke Outboard (Big Foot)
Finally I find someone with the same problem...Identical symptoms, including the techs that couldn't fix it.
Turns out it was a bad fuel pump (erratic pressure output). Probably caused by water getting into the fuel. (2 yrs ago, someone used an old can of gas to fuel the boat) Ever since then, I've had problems. Finally getting it fixed today (Wild River Sports, Trego, WI)
Try a different fuel tank and line first, its classic fuel starvation.
Also, unless yours is a 50 hp 4s list your engine make and specifications first, details matter.
2005 Mercury 50 HP Four Stroke Outboard (Big Foot) 
