550 SECA AIRBOX Tech Bulletin- Important

Attention Seca 550 owners: Do YOU know what's in your airbox?

Seriously, though. There's something about the airbox on the 550 Seca that's unique to that model, and represents its own potential issue.

It's this thing:




WHAAT?? What thing?




That rubber funnel on the bottom---




Here's another view---




It's NOT a drain. It's an AIR INTAKE. Yamaha calls it a "Suction Tube." When the bike is running, it draws air in all the time; lots more at high RPM.

So why is this important? It originally had a little foam filter element of some sort in the top of it. They tended to soak up oil and eventually dissolve.

Open your airbox, remove the air filter and have a look. You'll probably see a sight something like this:



The "filter" is completely gone in this pic, and you will likely find yours is too, or maybe just some gooey, oily remnants. NOT GOOD. This thing is sucking big air; it needs a filter.

Here's the "device" itself, out of the airbox:




Since it's rubber, the retaining discs are easily popped out for cleaning...




BUT IT NEEDS A FILTER:




In the past, I had cut my own out of a variety of different materials, with varying degrees of success. Yamaha originally had a foam "element" in there; I cut some out of a lawnmower foam air filter but it was difficult to get the thickness right and the discs cut even and sharp. Carving sponge rubber that light is an exercise in frustration.

XJ4Ever to the rescue. Working closely with chacal, what developed was a replacement filter element that comes as close to the Yamaha original as possible. I've ordered the "official replacement part" from Yamaha, and gotten a small, rectangular hunk of foam that didn't even remotely fit.

These, of course, do.

Once the tube and "X-Discs" are clean; simply fit the element, and work it into place under the lip of the tube with a clean finger tip:




Then reinstall the other retaining disc; you may need to use a small screwdriver as a "tire iron" to pop the last part of the disc under the lip.

Be sure to take a pair of hemostats or small needle-nose pliers and lift the metal retaining disc "up" against the inside of the lip to give the foam it's full space:




Then reinstall the whole thing in the airbox (assuming you removed it to begin with.)

It IS possible to change "filters" without removing the suction tube from the airbox; but I'd recommend it the first time so you can get it nice and squeaky clean.



All Happy.

Why is that thing there to begin with? Like I said, it's NOT a drain; I verified this by holding a small flap of paper near the opening while the bike was running. It is most definitely an AIR INTAKE. But why?

I have a theory: Based on its location, just under the inlet port from the breather, I think it's there to provide a "puff" of incoming air to diffuse the effluent coming from the breather. Why? Emissions? To keep the #2 carb from sucking more "oil mist" than the other three? Why only on the Secas, not the Max? Because Yamaha didn't expect the Max to spend as much time at high RPM?

You tell me; this is all a theory. What I DO know is that this thing vigorously draws air; and therefore it needs to be filtered.

Now, with kudos to Len, we have a solution. Part number will be HCP17795, he won't have them in stock right away but soon. Meanwhile butcher a foam lawnmower filter if yours is running wide open.

 

I have been waiting by the computer for Fitz to post up his latest Tech Tip. I was afraid that it was going to be something life threatening like a rear brake delamination. I had my air filter out two days ago to check it, but I couldn't recall if I still had my suction tube filter. As soon as I read this I rushed out to the bike, flashlight in hand to check it out. Didn't even finish my beer first!

Good news, my foam is still in place! Now that I know it exists, I will place it on my maintenance schedule and order a new foam next time I need something from XJ4ever.

Thanks Fitz. Keep up the good work!

 

Thanks and you answered one lingering question I had--- was it a "USA only" feature? Looks like a resounding no.

 

AHA!! so THAT was the missing "maintenance" bit.
Looks like Yamaha put a "pod" on the airbox just to mess with us.

 

Fitz, don't even have a seca, but I love your write ups!

 

Great write up Fitz. You might want to clarify how to remove that plastic funnel - does a person just yank hard from inside the airbox side to remove it? I really don't want to yank my whole airbox off of the bike if I don't need to.

 

The funnel is stiff rubber/neoprene.

Once the little metal "grates" have been removed, it is easily "deformed" enough to push it up into the airbox; or to "wrangle" it out from above.

Good point; I'll edit when I get a sec. Thx.

 

Thanks for that. When I yanked on the grates with needle-nosed pliers, the whole thing came up mind you. It bent the top grate a bit, but nothing I couldn't push back into shape.

Thanks for calling our attention to this little breather doohickey. I never would of noticed it otherwise.

 

does that amber colored drain tube have some sort of check valve in it to keep dirty air from being drawn in?

CN

 

The small-diameter vinyl tube? Nope.

But if you look inside the airbox, it's not just a simple hole either. There's a rectangular "box" over the opening that acts as a baffle of sorts.