Hello, John Talley here with Boats.net, and today we're going to be taking a
look at our 2004 Yamaha F225, and as you can see from the outside it's looking
pretty rough so I can only imagine what its gonna look like on the inside.
What's the best way to look inside one of these machines? Well we want to start
off by doing a compression test only. And you're only gonna need one tool to pull
that off, so let's step over and look at that. Alright, the only special tool
you're going to need, like I said, is a compression tester. If you need to pick
one up, why don't you reference that link in the description it'll take you straight
to a shopping cart where you can go ahead and get one. So once you've got
your compression tester I can go over there and show you how to take those
readings, so let's go.
So let's start off by popping the cowling off. Just three latches, then we
go ahead and lift it off. Next we have four or five millimeter Allens. Actually
two of these are missing, but they're gonna be here, here, here, and here. There
we go. Let's go ahead and pull all of our spark plug leads. When you're pulling
these try to grab them up on this part otherwise you run the risk of actually
pulling it out of the boot and we don't want to make it any worse than it is.
With the boots off let's go get those plugs out. Break them all loose. One of
the first things you would look for is the condition of your spark plug and
this one is hiding whatever it has to tell me because these are new. Alright,
this next part if you're still connected to your boat you won't have to do, but I
have to go ahead and bring up our power and the ignition connections so I can
get it to turn over while that's on the stand. So before we actually hook up the
tester I want to go ahead and hold the throttle bodies open. So of course if you
still have this on your your boat, all you need to do is put it neutral to open
your throttle. In my case we're gonna hold it up and with a zip tie. So let's
go ahead and get our fuel injection disabled. I'm just gonna unplug the
entire harness. We've already got our throttle bodies held open, and now we can
go ahead and start making some measurements. So let's go ahead and start
on our right bank and see what this engine's got.
More importantly what it probably doesn't have because I've been told that
one of more cylinders is down on compression. Alright, 50, 60, 70. 170. Not
too bad to start with. To get a uniform measurement you want to get each
cylinder turned over the same amount of time, so we're going to be aiming for
seven for each one. It's throwing things at me. 170, so that isn't looking very
healthy. We're down to 140. Got 190 here.
160. Last one. 130. I can go ahead and tell you, that uh with this much variation, this
engines got a problem. Plus, you'll notice we were higher up here and then we
dropped down on the lower cylinders. So whatever's going on it's indigenous to
that bottom side of the the power head. And judging by all the oil it's pumping
out there's something catastrophically wrong going on with those two bottom
cylinders. Alright guys that wraps this one up, but obviously we have a lot more
work to do to figure out what's going on on this motor. Listen, if you want to keep
up with that, Why don't you go and hit that subscribe button that way you can keep
up with whatever I'm working on next. Listen, if you need parts for your
machine, why don't you come see us at Boats.net and we can get you taken care of.
Have any questions or comments? Why don't you leave them in the section below and I'll
do my best to answer. We just want to say thanks again for shopping here with
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Have a great day.