Hello, John Talley here with Boats.net. Today we're going to be looking at the
fuel system on our 40 horsepower four-stroke EFI Mercury outboard engine.
Now we know this thing's been sitting up for a while, so it's probably a big mess
in there and actually the mechanical fuel pump on the outside-- the lift pump--
it's not even on the machine anymore. So somebody was trying to figure this out
and they gave up. Well we're not going to give up. But
let's step over to the table, look at the parts that I've assembled,
and hopefully we can get this thing back running.
So here we are. Basically I assembled every different aspect of the fuel
system, starting off with the mechanical fuel
pump. Then we've got a fuel filter and a couple of different rebuild kits
depending on what I find inside that VST tank. So now that we've
got all the parts assembled, let's dive over there,
get off that cowling, and get to it.
So with the cover off, it's obvious where we need to start. There should be
a mechanical pump, what they call a lift pump, right here and
it is nowhere to be found. This is the way the engine arrived to me,
so obviously somebody was doing a little bit of work on this and they got to this
point and then he stopped and then it set up for a long time. But
we need to go ahead and get it remounted-- or a new one mounted.
And then I fear or what I project is that the VST tank is going to be a mess
because like i said, this has been sitting for a while
and just the general smell that you-- I've picked up on it from the different hoses--
is the fuel has been in there for a long time.
But as I showed you on the table, I basically ordered every different
scenario so we can get this thing back up and running.
So let me grab the pump we'll get it remounted. It's actually missing a
hose that goes to the VST tank and I have a length of hose for that.
We'll get it remounted, go ahead and pull the VST tank, take it over to the
teardown bench, pull it apart, and then we'll see what we
have to work with. So our lines are as follows: this is
actually a water line that passes through for fuel cooling.
This is actually your input from the filter, and then this
upper one-- the smaller of the two-- heads over
to the VST tank. Now on the bottom side, a new
pump already comes with the O-ring that we need. And then we're just going to get
it bolted back up, get the lines connected, and this one
actually uses zip ties to hold things in place. Now if
you're not going to use the OEM zip ties, make sure that you order some
of high quality because they're going to be in a very
hot environment under this cowling. And the really cheap ones, they break
down quicker and then they're going to release.
And fuel swirling around the inside of an enclosure?
I think that would end poorly, so don't cheap out on
the good good stuff. Make sure that you actually buy
things that will actually survive under and in this environment.
Now the bolts that come from Mercury actually already have the thread locker
ready to go. Now if you're reusing yours or you're having to get a new set, just
make sure that they are stainless and then you want to add a little bit of
red loctite or thread locker before you do the installation on this.
So that is our, one of our water lines. In the second one.
And incoming fuel.
And outgoing.
But we are going to go ahead and zip tie these ends.
Get these tails cut off.
Up top is where the incoming fuel line will be connected eventually.
Then there's a couple of electrical connections because there's actually
an electrical pump inside of there and that's what gives it the high pressure
for the fuel injection system. So let's go and get that connection.
Pull it apart. Okay, once these hoses, they get older, they kind of can form to the
end of that barb and they don't want to let go because
they're getting brittle. And that should be a early warning sign
that it may be time to replace. Now look at that one. It actually had a split in
it. And then it looks like we've got two
eight millimeters. At that point we should be able to lift
it up. I want to leave these lines connected, because they're actually a
crimp type and we're just going to disconnect
from the bottom once we actually lift it up out of the cowling.
Eight millimeter or five sixteenths if you're working out of a standard box. All
right guys, I told you there was only two bolts?
There's actually three. There's one actually hidden down here. I was hoping
that it just had a, like a little bushing or a grommet that it was sitting
in that was holding it in place. No. There is one more eight millimeter
bolt down at the bottom, so guess what? We need to drop off the lower cowling,
but it's not that big of a deal. A few bolts on either side and then
it'll just peel off from either direction. Alright,
let's see if she's ready to shimmy off yet.
Yep. To help remove some of these hoses, usually uh, I'll just squeeze them to
kind of try to break them loose like this. That's a
drain at the very bottom. We should be able to take it over to the
tear down bench. Get those screws out, and take a peek
inside. Wonder what it's going to look like?
Check out the the fuel color when it comes out: has a nice yellow tint.
If you've never smelled stale fuel before,
it's pungent but that's not horrible. I've actually seen worse.
Let's do take note of which hose went where.
The one with the the covering is going to be on this side.
Alright, last one. This one is actually the output going to the fuel
injection system, so that's high pressure, and it is held in place
by this piece here. What you do to remove it is actually push in on this red
retaining clip and then pull. We'll attempt to
remove these screws just with a regular screwdriver. If not, I
may end up having to put it in the vice and then use an impact
screwdriver to get it removed because I really don't feel like
stripping one of these and having to extract it. Let's see what we got.
Oh yeah, she's going to be easy. But I have seen
in several cases, especially saltwater outboards, where these get
corroded and there's just no way to do it with a
regular screwdriver. You have to use an impact to pop them loose.
i don't want to disconnect these. I'm actually going to unbolt this
from the body and then it should all lift up together. I think that's the way
I'd rather go. I've got the necessary tools to replace
those, but why? Why disturb it if they don't need to be
replaced? Not horrible, but we needed to go in
there, because that fuel pump had completely
broken down. So what I'm going to do right now is
spend a fair amount of time getting all this cleaned up,
then we'll evaluate and see if there's anything that we can reuse,
and then replace as necessary. Now I have the VST
tank cleaned out fairly well, but I do want to go ahead and clean out this
drain because I'm betting it's stopped up. Now
one of the things that could have prevented some of this--
now I realized the engine didn't run-- but if you know you're not going to run your
engine for a while, go ahead and put some fuel stabilizer in there, draw it into
the system by running it for a few minutes, and then
drain it all out. That way it's in the system and it has a better
chance of staying ungunked because obviously this has been sitting in fuel
for a long time and well, you see the results.
But even if your engine is not running, go ahead and drain it,
get as much fuel out of it as possible. That way you'll minimize the amount of
damage that we're having to replace in here.
Yeah, good to go. Now let's take a look at the float,
get it out of the way, look at the seat, see if we need to replace it or just the
needle itself. Then we're going to address that pump.
I'm looking at the tip
of this needle and it's actually bent a little bit and it's
pretty much as hard as a brick. I mean, this tip is actually made out of rubber
so it should have some flexibility in there.
It has not broken yet, but it is getting closer.
So we are going to go ahead and replace it. So let's go and remove
our pump. Be careful with these connections.
Yeah, keep in mind where they are: black was over here in line
with the output tube, red was over here.
So now let's go ahead and remove this plate
because I'll wager that there's debris on top of it
and we need to get all of that out.
Yep, a little bit down there. Actually I had two different pumps here because I
wasn't sure which one was going to go in there. It is
the older style, which fortunately I have. So we'll be sending that other one back.
So the one we will be using basically just has
this bottom O-ring and this little length of hose that actually goes into
the top. So this is the one we're going to be after.
This seat-- like i said, we've already got one,
let's replace it.
This one is probably okay, but with this other amount of damage I'd
rather just replace it all and be done with it.
Alright we've got our seat in, we've got this rubber piece in for our
fuel pump, let's go ahead and get this plate back
in place.
Now we've got that screw started, let's go ahead and get our
float back in.
There she goes.
Then our electrical connections.
What I'm doing here is just bringing the spade clips back
in, compressing them back down. That way they get a good grip
on the connection. There we go. Well that's it, let's get it mounted to
the base and then get this thing put back together.
She's ready to go.
I think everybody's going to reach and everybody's in the right direction, let's
go and tighten these down.
Well all right guys, that's pretty much gonna wrap this up. Only thing I have to
do now is put on that lower cowling put on the
cover and she's ready to go out the door. Well listen, if you need these or any
other parts for your boat, why don't you come see us at Boats.net and we can get
you taken care of. Have any questions or comments? Leave
them in the section below and I'll do my best to answer them.
We just want to say thank you for shopping here with us at Boats.net and
we will see you in the next video. Y'all have a great
day.