Discovered Dirt In Carb! Opinions Requested - 07 WR450


55 replies to this topic
  • ETP

Posted November 30, 2007 - 12:41 PM

#41

As far as dirt in the bowl, I'm going to try and address it with one of these things: http://www.7602racing.com/prod_t6cf.php I have two on order. If nothing else, it ups the bling factor!


The dust thru the carb hose theory is new to me.
These filters look like a good way to block the dust, however, the dust in the front of my carb appears to be all very fine particles. Seems that the hoses would suck just about anything airborne thru them, not just very fine particles.:thumbsup:

  • SXP

Posted November 30, 2007 - 12:59 PM

#42

The dust thru the carb hose theory is new to me.


More below, you must have missed it:

This was recently discussed on the YZ side, with none other then James Dean weighing in. The culprits are the vent tubes hanging off the bottom of the bike. Read this thread: http://www.thumperta...ad.php?t=574328



  • ETP

Posted November 30, 2007 - 03:13 PM

#43

Hey guys, I saw this thread and thought I might post a couple of pics of our filter. This is our filter after about 7 hours of riding through dry desert trail and two track roads. This is a little dirtier than what is typically found, but I usually ride on the track or mountain trails which tend to be a little less dry and dusty. When cleaning the filter I have found dust, dirt and sand particles, pieces of wood, and once a small blade of grass. This filter was installed on a 2006 Husqvarna TC 450 with a 41mm FCR carb. While the amount of contamination sucked up the tubes might vary, and exactly how much damage it causes might be up for discussion, whether or not they actually do suck stuff up is not. Sorry for the low picture quality.

Clay

This is the front side of the filter.
Posted Image

And this is the back side of the filter.
Posted Image


Thanks for the pictures.
Wow. Never thought of it before, but suction is what draws the gas/air vapor into the combustion chamber, so why not foreign matter thru the breather hoses. I guess the real question is how much is too much?

  • MotoGoalie

Posted December 03, 2007 - 07:24 AM

#44

Well, I'm more confused than ever. From the looks of the vent filters right above this post, it's reasonable to assume that fine dirt is getting into the carb/engine via the Air filter AND the vent hoses.....No?:thumbsup:

  • RickSanson

Posted December 03, 2007 - 08:05 AM

#45

After all this effort in finding, diagnosing and trying to resolve the dirt in carb problem, I'm going with three things on this:

  • On my 07 WR450, the cage and airbox seal aren't properly sealing
  • There will be dust that gets through the filter (Per James Dean)
  • There will be dust that enters through the vents
I'll do whatever I need to fix these three things!

  • Frostbite

Posted December 03, 2007 - 08:38 AM

#46

I going to throw a curve into this discussion - has anyone considered that some of the dust could be caused by a bit of blowback from the cylinder through the carb? Maybe a bit of burnt mixture crap gets pushed onto the slide during deceleration popping/backfiring.

75% of my riding is in pure snow - zero dust - and I still get a bit of grit in the slide bore.

Just thinking outside the airbox.....

I also have my upper vent tubes rerouted through a small collector with a filter in it, but I think it would let fine dust through, it's more to keep the ravens out.

Posted Image

  • MotoGoalie

Posted December 03, 2007 - 09:20 AM

#47

ok, what about the metal grinding metal, unlubricated action, in the bore, the slide and on the spring and rotating throttle do-hicky (official GYRT part name:p ), I think some of this is from that kind of action as well.

  • C-P

Posted December 07, 2007 - 06:25 PM

#48

I'm sure everyone is aware of it, but no here is dealing with the defective filter cage hole in their 2007, are they?

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  • DirtyDude

Posted February 11, 2008 - 02:25 PM

#49

Well, I'm more confused than ever. From the looks of the vent filters right above this post, it's reasonable to assume that fine dirt is getting into the carb/engine via the Air filter AND the vent hoses.....No?:)


I've been researching this for a long time and I'm convinced that dirt can find it's way up those vent lines and into the float bowl. I ordered a tube filter kit from KevinsCycleRacing (dot com) for $20. Cheaper than others I've seen, and he includes one-way valves for 3 lines that will keep out any water that might want to travel upwards during a crossing. He also recommends putting two of the tubes up under the tank to continue venting during a river crossing. Lots of people run them into the airbox, but he says don't do that because the airbox vacuum may affect carb operation. I will post my results when available. I've been getting sand in the bottom of my float bowl all too often. (Yes I have an in-line fuel filter, and yes I grease the heck out of my near-new UNI filters that are generously oiled with air-filter oil.)
I also think James is spot-on when he says the air filter cannot block all dust. All you can do is keep the filters as clean and as nicely oiled as possible.. :applause:

  • mvryder

Posted February 11, 2008 - 02:29 PM

#50

Also just to trow out there again. The air boot does leak at the junction to the filter face plate and to the AIS elbow. I tested the whole assembly in the bath tub.....it leaks.

  • DirtyDude

Posted February 14, 2008 - 07:45 AM

#51

I tested the whole assembly in the bath tub.....it leaks.


Whoa! I thought I was doing some serious research on this, but mvryder, I think you have me beat taking the airbox off the bike and cartin' it into the bath tub! Interesting data point, and good work! :) :applause:

  • 97smoker4x4

Posted July 20, 2008 - 07:20 PM

#52

I just got an 03 wr450, and noticed some dust on the inside of the filter boot on mine as well. The only other bike I have owned that I noticed this problem with was an 02 cr250, and that was due to a bad seal at the boot to airbox juntion. This was a well known problem with this bike, and some good quality rtv fixed that problem.
It sounds like the WR's problem may be a poorly fitting filter cage. If this is the case, I wonder if twin air's aftermarket aluminum cage (powerflow kit) would work. It is supposed to increase airflow by eliminating the backfire screen. The filter is treated to be flame resistant. Has anyone tried this filter kit? Is it worth the $140 for the kit?
thanks

  • godhappan

Posted July 21, 2008 - 06:39 PM

#53

I just got an 03 wr450, and noticed some dust on the inside of the filter boot on mine as well. The only other bike I have owned that I noticed this problem with was an 02 cr250, and that was due to a bad seal at the boot to airbox juntion. This was a well known problem with this bike, and some good quality rtv fixed that problem.
It sounds like the WR's problem may be a poorly fitting filter cage. If this is the case, I wonder if twin air's aftermarket aluminum cage (powerflow kit) would work. It is supposed to increase airflow by eliminating the backfire screen. The filter is treated to be flame resistant. Has anyone tried this filter kit? Is it worth the $140 for the kit?
thanks



X2 I was wondering the same thing

  • mvryder

Posted July 22, 2008 - 08:13 AM

#54

It is likely getting through the filter. And I use twin air filters with a liberal coating of Maxima oil.

I have an 07 450 and I disassembled the air box and siliconed it all up. I also modified the cage guide so the cage fit much tighter. None of that really changed the post-dusty-ride results.

Also I added a piece of filter foam at the opening of the air box to try and distribute the dust better and not get it to concentrate on one spot on the filter so much. Still an ever so slight amount of super fine dust gets through.

I also replaced the AIS elbow and made a plastic plug and siliconed that in to place too. Nothing there either.

I am plum out of ideas.

  • TooFast

Posted July 25, 2008 - 08:14 AM

#55

IMO, presence of intake boot dust, is why you need to keep a well oiled filter , with fresh quality sticky oil like Belray, on your foam filters. There are some other good oils but this excludes NoToil, motor oil (like the old days), K&N's, etc

  • Dominion

Posted July 25, 2008 - 08:42 PM

#56

Are you folks greasing the mating surface of the air filter and the air box? I always use some Moly grease and put a bit around the part of the filter that comes into contact with the air box. I have never had issues with dust, dirt or anything in my car. I ride a lot of sand and in a lot of dusty situations too.

~Brian




 
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