Hello John Talley here with Boats.net. In this video we're going to start
tearing down the powerhead on our 2004 Yamaha F225. Listen, there's going
to be no special tools involved with this, so I will call out whatever tool
I'm using to start the breakdown process. We're going to pull the cams, get the
head off, take a look at those valves, and see if any of this can be reused when we
go to rebuild it. So if you're ready we can go over there and get started.
Go ahead and get this mounting plate out of the way, and then we should be able to
release the tensioner and get the belt off. Now let's go and relieve tension. The
way you do that put a 10 millimeter in there, pull it slowly, maybe 10 foot
pounds, and you'll see the pin start to relax and it comes around. At that point,
you can put in your 5 millimeter pin and it'll hold it there. Not that tough. There
we go. Gonna go and pull the tensioner all the
way off and just put it to the side. Next let's go ahead move this transition
plate for the throttle body linkages.
Next let's go ahead and move the cam gears. You want to use an impact on these
because you can't allow these to turn, otherwise you're gonna bend your valves.
Let's go and get our drive sprocket. Taking off the sensor right here.
There's a ground strap running in between the two heads. Let's go and get
that out of the way before I forget. And then we're gonna pull the valve covers
and the exhaust plates and take a look at the top end. Let's go and remove the
exhaust plates. And you'll notice that they are numbered 1 through 14 for each
side. We're actually gonna do this in reverse,
1 through 14 represents the tightening sequence if you were putting it
together-- we're taking it apart. So we're gonna start at number 14 and work our
way down to 0. There we go. Careful when you doing that-- don't damage
the surfaces. That is not a good thing 'cause that is getting ready to snap.
We will come back to that one later. Alright, now back to a problem child.
Yep, she broke.
There we go. They do give you a point to pry right down at the bottom. Next, let's go
for our covers. What I was worried about is we're gonna have damage to the cams
caused by oil starvation, because we know that there's evidently an intrusion
of the old galley way somewhere down in the block-- to be determined where that is.
We won't really know until we get the cam caps off. But before we pull the
tensioner and the caps, let's go and pull off the other cover. Now let's go ahead
and start with our tensioner over on this bank. Now we can take off our caps.
So we're going to go one, two, three, four.
Alright let's keep going. So that's one, let's get two.
The sequence to pull the heads on this side is going to be one, two, three bolts
on the outside. Now the torques on the inside we go four, five, six, seven, eight,
nine, ten, eleven. And at that point, we should be able to remove it. Already
broken free, so we can just go straight up. And once we pull off that last one,
the head will be free. We'll still have to break it loose, but keep in mind there's
nothing else holding it except the dowels and the head gasket. See if we can get
here to come loose. What I'm looking for here is to see if the head gasket was
blown anywhere. It does not appear to be from what I see so far.
We might be able to reuse these, I won't know until I get completely broken down
and cleaned up. But those two areas might explain why we were losing so much
pressure on compression and on the leakdown. It looks like it was blown through
right there. Just remember correctly, if you go back and watch that video, it was
this this one they had like a 75 or 85 percent loss on leakdown. Let's go ahead and get that
tensioner out of the way.
There we go. So let's go ahead and start attacking
the the starboard side, starboard bank. We start up with-- on the cam caps-- one, two,
three, four. And then we finished with number five. That is the one cam that
didn't have any tension on it with any of the valves.
What I'm doing now it's just cleaning the oil off the top of the tappets.
I'm gonna go ahead and mark these. I was a little bit lucky on the other side that
none, um, fell out. I don't want to take that chance over here. So we're gonna go
ahead mark them as to what location that they started in, that way they can go
back to the same place. So let's go over the loosening sequence on this. So it's
going to be one, two, three, four, five, six, seven, eight, nine. There we go. As you can
see, I already have all the tappets numbered because we do plan on reusing
these heads if they do check out at the machine shop. So we want them all to go
back in the same location. So let's go ahead and start pulling them out. I'm
just using a magnet to grab them from the side. Now keep in mind as you're
doing this, if you just used a sharpie to write this on there? One spray of contact
cleaner and all that goes away. So you have to be careful when you're cleaning
these up. I like to lay them out in the same orientation that they come off just
in case a number gets wiped off.
Before we start pulling them out, I just want to do a quick little test on this
one. What we're gonna do is actually spray a little bit of contact cleaner
into each port, that way we can see if there's an obvious leak on the valves. So
we'll start over here on the intake side and see if any of them are leaking. See
that one? Now if you've noticed I'm wearing gloves
as I'm handling this thing, because all these edges are like razors and they
will open you up in a heartbeat. Let's see what we've got. Alright that's all
right. Uh-huh. Look at that one. See it leaking?
And let's go for the last one. OOP, there she goes.
We have at least one cylinder that we know is leaking. Now so when it comes
time to put this back together after we've gotten the valves all cleaned up,
we're gonna put a little bit of Prussian blue, that way I can look at the seats
and see where they're actually riding on the valves. And, if I have to recut the
seats, then so be it. But I'm more than likely I'll just be able to lap the
valves to get them to seal properly. Just a couple of turns, then we can reach in,
grab the keepers, and then release it.
Both of them, one shot. Normally if I had done that first test and there was no leakage,
I'd be really concerned about getting all the valves right back where they
started. Well if I'm gonna have to resurface the valve seats and/or the
valves? I'm not worried about it so much. I am still going to keep them organized,
but at this point it's not hyper critical that they all go back into the
same place that they came out.
There you go. There you are.
Well, one down, one to go. You get the idea of the process. Now what
I'm going to do next once I finish breaking down the other one, is go ahead
and load them up, take them to the machine shop, let them get them cleaned
up, and resurface that head. And then we will take a look at the valve seats to
see if we can get them to straighten back up. Well listen if you need any
parts for your machine, why don't you come see us at Boats.net and we will get
you taken care of. Have any questions or comments, leave them in the section below
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I'm working on next. Just want to say thank you for shopping here at Boats.net
and we will see you in the next video. Have a great day.