140hp Mercury Outboard Issues

Kilpack

Cadet
Joined
Jun 9, 2013
Messages
14
Hey All,
I just heard back from a mechanic at the Buckboard Marina on Flaming Gorge Res. and he informed me (after 2 months of having my boat in his shop I might add) that the main barrings and the "laborite seals" (?) are going out on my motor. I am not 100% sure what he's talking about... he says that the last engine of this issue had to be shipped to Oregon (we are in Wyoming), and it cost $4000 to get back. Can someone relay this to me and let me know what is going on from what I've been told, and if he is accurate on the severity of this problem?

Backstory:
Bought the boat (1978 Glastron w/ 1978 140hp inline 6 Mercury engine) from a guy in Idaho for $2500.
The boat ran great the day we bought it, rev'd up with a load and just, all in all, seemed great THAT day.
Hasn't ran right since we brought it up to Wyoming... have had it [floating] out on our local lake twice without making it past the dock, except the one time I drifted away and had to paddle back...
I've re-jet it for my altitute which is about 2500' higher than where bought from, and fixed a leaking carb plug.
I've had the mechanic replace the wiring harness. I need a new gearbox, the existing one keeps locking up but the engine will shift ok.
The engine passed the compression test (not as greatly as hoped, but still within a good threshold).
It needs a new, lower pitch prop for altitude (old one was drilled).

My wife and I are depressed, haven't been able to take the boat out once since the day we bought it...
Thanks ahead of time for your help and advice!
 

Kilpack

Cadet
Joined
Jun 9, 2013
Messages
14
Re: 140hp Mercury Outboard Issues

Does anybody know where I might be able to find these "laberince seals" this guy is talking about?
 

calvinator

Petty Officer 1st Class
Joined
Sep 22, 2010
Messages
286
Re: 140hp Mercury Outboard Issues

Couple of thoughts....

These motors are a labor of love. They are older and not a lot of mechanics want to work on them. Either they don't want to deal with the old stuff, or the hours of labor to get them right the customer doesn't want to pay for. Maybe he is giving you a line, or maybe your bearings are shot. Never heard of laberience seal, but there are some seals in the powerhead that are labor intensive to replace.



That motor in perfect running condition is a $1000-$1500 motor. Don't spend $4000 on it. And it also sounds like you have other issues with the motor too.

Assume the motor is shot. Part it out, easily $500 in parts there.

Time for a different motor.

Start searching for a similar 1970s-1980s Mercury Inline 6 Cyl 1150 (115hp) or 1500 (150hp) in the $1000 zone. Plenty of them out there and compatible with your control box & steering. If you stick with that vintage motor, you should start doing a lot of the work yourself to avoid the run arounds from mechanics that don't want to work on them. I have a 1975 Mercury. I maintain and repair it myself. Plenty of parts and online help to DIY!


You can also shop the marinas for used motors and installation.. Probably $2000-$3000. My local marina has a perfect 1989 Yamaha 150HP for $1750 installed.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,616
Re: 140hp Mercury Outboard Issues

Does anybody know where I might be able to find these "laberince seals" this guy is talking about?
They are labyrinth seals on the reed blocks that ride on crank., if worn motor will have a tendency to die going into gear, wont take fuel on acceleration. Other issues can cause same problems such as: incorrect timing and linkage adjustment, incorrect gear ratio, over propped and fuel starvation.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 140hp Mercury Outboard Issues

If you are half way mechanically inclined and willing to read and follow directions, we can direct you thru testing and adjusting your motor.

The fact that the motor starts and runs is good, it is all in the details, the older 6's can be very finicky but once dialed in they are a treasure.

As Fazt said, many shops done want to mess with the older motors, younger techs are not familiar with them.

Old timers can go either way, some hate 'em, other miss them and love to have one come in so he can give it some love and hear it sing again.

Go get your boat and a halff decent compression tester, test it and tell us the numbers.
 
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