HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
AVMAN

Crankcase breather tube SUCKS (sand) 09 450

18 posts in this topic

I'll try and make it short and sweet. I have a new to me 2009 yz450f, I was told less than 10 hours on it when I bought it in January. Two of my friends and I now all have the same bike. Before the Florida trip I changed the oil and filter (using yamalube and K&N paper filter). After we came back from Florida I finally got around to changing the oil and filter again today and CRAP did it have a lot of sand in the filter! Mostly packed in around 3 or 4 folds in the paper near the bottom where the holes for oil transfer are. Anyway I called my buddy who was also changing his oil today and asked him what he saw when he took his filter out and he said "a bunch of sand". I don't know how concerned I should be about this, but I'm pulling the valve cover tomorrow to check that out and clean any sand out of there too. I took the breather hose off tonight and shot some simple green in it and then shot the garden hose through it into a bucket and the water was filthy. Soon to come will be a reroute of the breather hose into the airbox with a filter on it. Just a FYI to anyone wondering if it picks up sand...it can and did. Also, my gas boiled a lot on the trip, the yamaha rep at daytona told us Florida pump gas is crap (higher than 10% ethanol and lots of water in it) which would lower boiling points. I took out the check valve in the fuel vent line per the tech's advise and had no problems but my buddies were getting vapor lock. Any help on this front? Other than that I loved my first trip on the new bike and love 4 stroke power.

Edited by AVMAN
misspelling

Share this post


Link to post
Share on other sites

2010 does it too.

These lines need to be filtered or routed directly into the intake boot between the filter and the carb/throttle body. To add, there are a few threads on this that go into quite a large discussion on solutions issues etc.

From what I have read, the breather tube length is tied into the displacement of the engine, in which, air is pumped out and into the hose. The engineering behind the length of the breather hose is this;

It is just long enough to ensure that the negative pressure from the crankcase (Piston moving from BDC to TDC) will not suck outside air in because of the previous positive pressure (Piston moving from TDC to BDC).

I am having a hard time explaining it but if you search you will find an explanation by greyracer.

Problem is when the bike is first started it can sometimes draw in outside air, that means if your hose is submerged in any kind of fluid (sand or water) it could draw it into the head.

I still haven't done it, but when I find a good source for plumbing I plan on routing mine into the intake boot. I want to find a good rubber grommet hose adapter in which I can properly seal it to the intake boot. I'm just nervous that the seal might break or come loose, allowing unfiltered air to enter the engine. When I find a good adapter or method I'll go for it and post pictures for sure. I suppose I should search too, as I'm sure there are others with other brands of bikes who have done this. Word is that the WR and CRX models have the hose routed to the intake, pretty sure anyways.

Share this post


Link to post
Share on other sites
I'll try and make it short and sweet. I have a new to me 2009 yz450f, I was told less than 10 hours on it when I bought it in January. Two of my friends and I now all have the same bike. Before the Florida trip I changed the oil and filter (using yamalube and K&N paper filter). After we came back from Florida I finally got around to changing the oil and filter again today and CRAP did it have a lot of sand in the filter! Mostly packed in around 3 or 4 folds in the paper near the bottom where the holes for oil transfer are. Anyway I called my buddy who was also changing his oil today and asked him what he saw when he took his filter out and he said "a bunch of sand". I don't know how concerned I should be about this, but I'm pulling the valve cover tomorrow to check that out and clean any sand out of there too. I took the breather hose off tonight and shot some simple green in it and then shot the garden hose through it into a bucket and the water was filthy. Soon to come will be a reroute of the breather hose into the airbox with a filter on it. Just a FYI to anyone wondering if it picks up sand...it can and did. Also, my gas boiled a lot on the trip, the yamaha rep at daytona told us Florida pump gas is crap (higher than 10% ethanol and lots of water in it) which would lower boiling points. I took out the check valve in the fuel vent line per the tech's advise and had no problems but my buddies were getting vapor lock. Any help on this front? Other than that I loved my first trip on the new bike and love 4 stroke power.

Had the same scare as you, but I sucked in a bit of mud bog. Breather hose has been re-routed to the air box and the problem is no more.....bike looks cleaner now without the stupid hose running down the side.

Share this post


Link to post
Share on other sites

Yeah I've read about all the threads on different opionions on how to reroute the breather hose, so I've got that information when it comes time to do the mod. However, my main reason for postings was that during most of those discussions there was some arguments as to whether it was necessary to even bother with it, because the hose shouldn't really suck up dirt. I don't remember dumping my bike in the sand at all, just following some guys sometimes who sprayed me with sand coming out of turns ( I returned the favor later). My point is I only rode there 5 days and that was enough to pack some sand in there pretty good so I hope someone else can avoid the problem before it happens to them. Another benefit for me will be the fact that we cross a lot of water here in Kentucky so the reroute will be great for that also.

Share this post


Link to post
Share on other sites

Ok, took the valve cover off today to take a look and there was more sand in there than I would have ever liked to see. Used q-tips to get as much of it out as I could and I guess I'll just change the oil a lot until the filters come out clean, probably after every ride for now. We got the breather tube re-routed between the motor mounts and into the airbox, I'm just waiting for my UNI breather part UP-123 to show up. I'm really frusterated that Yamaha has this design, and if they knew about the problem why I didn't know about it. Just to recap....I have a 2009 YZ450f and the way the crankcase breather tube is routed stock, IT CAN SUCK SAND INTO YOUR ENGINE. We had 3 of these exact bikes on our trip and all 3 of them had this problem.

1 person likes this

Share this post


Link to post
Share on other sites

I've read about this issue here on TT before, but read that some people didn't have an problem. I'll be heading into the sand in a week or so, before the tracks around here are rideable (snow/muck) and after reading this again I'm going to re-route my breather. An ounce of prevention.......

Thanks for posting.

:thumbsup:

Share this post


Link to post
Share on other sites

I've posted these pics before a long time ago, I'll go ahead and throw them on here just to show one of the options that I feel has worked out really well...

The set-up: (quick release on the clear tube allows me to clean it easily without having to remove the top zip-tied portion)

DSC04477small.jpgDSC04478small.jpg

The routing: (plastic T zip-tied to the motor mount)

DSC04486small.jpgDSC04479small.jpg

Smaller drain tube meeting up with carb vents:

DSC04481small.jpg

Top tube routed through the shock res into the airbox:

DSC04485small.jpg

Filter on the end in the airbox:

DSC04463small.jpg

Edited by GOOSE 07 YZ450F
added a close up of the fittings...

Share this post


Link to post
Share on other sites

Expensive ass Loudmouth ($150)...Bought back when I had money burning a hole in my pocket (unfortunately no longer)...Make's for super easy filter changes, does NOTHING for performance (like they claim)...In hindsight I wouldn't have done it...

Share this post


Link to post
Share on other sites

Goose, I like that setup! :thumbsup:

Where did you get your Tee-fitting? Is it a Yamaha part, an automotive emissions part, Home Depot sprinkler fitting, or ????

So you don't have any sort of check valve or anything on your small clear line; it's simply routed right along the carb's vents?

Thanks for posting this!!!

Jimmie

Share this post


Link to post
Share on other sites

What's the deal with the clear hose? Is it sealed on the end to trap vented oil and clear so you can see if it's full?

Share this post


Link to post
Share on other sites
Where did you get your tee-fitting?
It's just two white pvc fittings (one "T" and one "angle") that I grabbed from the local hardware store, and used plastic/rubber epoxy to join everything, then sprayed it with black high temp silicone spray...
So you don't have any sort of check valve or anything on your small clear line; it's simply routed right along the carb's vents?
Correct...
what's the deal with the clear hose?
I used the clear hose simply to see what, if anything, was being sucked up or spit out...
Is it sealed on the end to trap vented oil and clear so you can see if it's full?
No, I didn't want to block it off at all because I didn't want any pressure differences from the length of the line, or the filter...I'm not worried about the open end of the small line, because any slight resistance would just make it suck from the airbox instead...So say you've got your rear tire buried in the sand to hold the bike up during a break in the dunes and that clear line is sitting right into the sand when you go to fire up the bike, it'd just suck from the airbox line instead...Or the same principal applied to riding through a creek or mud...

Share this post


Link to post
Share on other sites

^^No prob Diesel...Glad I could contribute...

I think it's worked out well, because I do get a little drainage from the clear line (with no grit being sucked in), and no oil on the filter end (which was predicted, but never happened)...and it's easy to blow out the clear line from time to time because I used that quick clip (part#90467-140A4-00 $4.50)

Share this post


Link to post
Share on other sites

I like the idea of putting a tee and running a clear hose down to the carb vent lines but it wouldn't work well with my configuration. I use a pcv valve at the end of my tube as it prevents anything going up, just lets it vent out.

Share this post


Link to post
Share on other sites
I use a pcv valve at the end of my tube as it prevents anything going up, just lets it vent out.
Nice thought, but PCV valves are too restrictive in the direction that they do flow to serve the purpose very well.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0