06 450 Breather / Airbox mods...

[MHill]

...Before I get directed to "do a search", let me add that I already have, and still have many questions. I just bought an 06' and living in Washington, let's just say that there is plenty of water. Can anyone who has done this mod, moving the breather hose into the airbox post any pictures and part numbers (air filter, etc.)? I've already started braking down the bike to grease the barings and would like to get the breather mod out of the way while I'm at it.

Thanks in advance

[grayracer513]

Here's what I found with a search: ?

Suggestion #2 is what you were after.

Breather mods

[MHill]

Thanks, gray

I found that one during my search, I'm just a little confused still. I'll never claim to be the most mechanical person on earth.

[grayracer513]

Confused by what, specifically?

[aford541]

I think I am going to run my hose into the un filtered side of the airbox up high, or maybe I will call my buddies at Yamaha of Troy and ask what they do.

[SureBlue]

Don't run it in the filtered side, you don't want to suck air from crankcase.

The best place to locate the tube on '06 is the upper right corner of the airbox, no space in the upper left like there was earlier.

I'll post pics when mine is done.

[DPW]

I'll post pics when mine is done.

Thanks ...

[MHill]

Don't run it in the filtered side, you don't want to suck air from crankcase.

The best place to locate the tube on '06 is the upper right corner of the airbox, no space in the upper left like there was earlier.

I'll post pics when mine is done.

SureBlue,

Thanks man!

?

[G 9.5]

Why is this breather tube mod necessary? Seems like on 06 at least, that there is constant outward pressure.

[FFRacing79]

Don't run it in the filtered side, you don't want to suck air from crankcase.

Really????

[grayracer513]

Why is this breather tube mod necessary? Seems like on 06 at least, that there is constant outward pressure.

There is in operation at speeds over an idle, in general, at least it's a net outflow, but the slower the engine turns, the more the airflow becomes a pulse matching the up and down travel of the piston. At a normal idle or above, there is not enough time for all of the air displaced by the down stroke to flow out through the breather before the piston reverses itself. That means that there is also not enough time to draw the full 450cc of air in, and the first part of the upstroke will be spent reversing the pressure from positive to negative anyway.

The trouble starts when you are cranking the engine with the breather submerged in water, fine sand, or the like. Under that circumstance, the upstroke of the piston can pull in the entire displacement of the engine, and may be able to pull a load of water or a little sand in (the breather tube does not hold 250cc, much less 450)

Running crankcase air into the intake is not ideal, but it isn't anything to be terribly concerned over, either.

[FFRacing79]

If you were to replace your breather tube with a clear hose and submerge it in water, at 9000rpm it would draw about 2" of water up a 1/2" hose. At idle it will blow a few bubbles, but once the rpm start to climb, it will draw up the hose but not as far as you would think.

Ideally, you would want to vacate ALL bottom end pressure and not allow it to return. Since this is not possible without a good oneway valve on the breather, having the intake assist is the next best alternative ala Honda. Tdub

[SureBlue]

Really????

Since I can't tell if you're sarcastic or what, please let me add the following:

I would not like to get anything inside the airfilter but filtered air. If it would happen that the bike was overfilled with oil, would it not get puked out from the breather hose right into the carb if the hose was connected to the filtered side of airbox?

And what if the hose got loose from airbox, would it not suck unfiltered air into the carb?

I have not done the mod yet, but will post the pics when it's done. All I can see is that there is limited space also on the right side of the airbox due to the shock.

[Lizard 1]

Since I can't tell if you're sarcastic or what, please let me add the following:

I would not like to get anything inside the airfilter but filtered air. If it would happen that the bike was overfilled with oil, would it not get puked out from the breather hose right into the carb if the hose was connected to the filtered side of airbox?

And what if the hose got loose from airbox, would it not suck unfiltered air into the carb?

I have not done the mod yet, but will post the pics when it's done. All I can see is that there is limited space also on the right side of the airbox due to the shock.

I might be wrong, but if oil gets into a puking mode and comes out of the hose, you have more to worry about than oil getting into the carb...

You're gonna have some serious engine work to do so, oil into the intake is the least of your worries...

[SureBlue]

I might be wrong, but if oil gets into a puking mode and comes out of the hose, you have more to worry about than oil getting into the carb...

You're gonna have some serious engine work to do so, oil into the intake is the least of your worries...

It's the natural way for excess oil to come out and does not indicate any serious trouble other than a person's ability to fill in the correct oil amount, which can indeed easily be done if you don't know the procedure of checking the oil level of a dry sump.

[SureBlue]

I'll post pics when mine is done.

Did the mod today. There's actually not enough space anywhere in the '06 airbox, which is quite a bit different from previous years. So I ended up routing the hose thru the mudflap.

Rerouting:

Above the shock reservoir and thru the mudflap right corner:

You can see my fingertip thru the 14 mm hole I drilled on the mudflap:

Here's the hose coming thru the tight hole into the airbox:

Also ziptied an endcap with filter on the hose:

The hose is now ready routed:

Now I can stall the bike in deep creeks and dump it in sand without fearing of water or sand getting into the engine.

??

[cowboyona426]

Nice job with the pics SureBlue. My question, though, is "is this really necessary?" I found on my 426 that the carb breather hoses being submerged was a bigger problem than having that hose under water, in fact I never had an issue with that hose sucking water, dirt, sand or anything up it. I wonder what is so different about the 06 that makes this such a problem?

[SureBlue]

Nice job with the pics SureBlue. My question, though, is "is this really necessary?" I found on my 426 that the carb breather hoses being submerged was a bigger problem than having that hose under water, in fact I never had an issue with that hose sucking water, dirt, sand or anything up it. I wonder what is so different about the 06 that makes this such a problem?

Yea, I have earlier only heard of theories, but after reading horror stories and seeing nasty pics what had happened with some '06 bikes I don't want to take any chances. It was simple and easy to do, so why not, can't hurt can it? Maybe I'll reroute the carb breather hoses too...

BTW - I still owe you that beer, remember?

[IMCanadian]

Thanks for the great pics.....what type of filter is that on the end of the hose?

[ajc]

Is there any thing wrong with just routing the breather hose down along the shock with the carb hoses if your not concerned with water. Newbe to 4-stroke.