sand in oil filter


26 replies to this topic
  • rasta

Posted November 17, 2004 - 07:51 PM

#1

have a 03 yz 450, keep finding sand in oil filter, bike has never been in fine sand like this, any ideas from were it came from,thanks

  • yzf450jack

Posted November 17, 2004 - 08:04 PM

#2

Are you sure it's sand :cry: most of the stuff you find in your oil is from the clutch .That's normal

  • rasta

Posted November 17, 2004 - 08:27 PM

#3

yeah it is sand just like fine grits you would find at a beach, only shows up in the filter, this is my third engine and dont want to break another one, thanks for the help

  • grayracer513

Posted November 17, 2004 - 08:57 PM

#4

If it's never been in sand, it shouldn't have sand in it, and no dirt of any kind should be able to enter the crankcase. Remember that your transmission will normally shed a considerable about of steel into the sump, which is why I don't think it should share oil with the engine. That could be it.

If you really want to know, you can get an oil analysis done at most big fleet maintenence shops for trucks and heavy equipment. They will tell you exactly what's in it.

  • yzf450jack

Posted November 17, 2004 - 09:01 PM

#5

Wow three motors! Do you ride in sand! Is someone that don't like your bike putting sand in it :cry: clean it out then mark the filler cap so see if it was tamperd with :cry:

  • YZ250F_Rider

Posted November 18, 2004 - 03:39 AM

#6

The 450 can suck sand up the vent tube just as easily as it can suck water up it. Hold a dollar next to it while it's idleing some time.

Route it like this and it wont get sand in it anymore.

http://www.forumpict.../IMG_0022_1.jpg

I used one of these to mount the loose end to the boot. Just cut the nipple off of it right at that clamp groove.

http://www.forumpict.../IMG_0019_1.jpg

  • Thumper38

Posted November 18, 2004 - 04:52 AM

#7

I thought the breather blows out! this is scary, so in a very dusty race you are actually sucking dust? what about the oil residue that is expelled from the breather,it will be sucked into the engine?

  • YZ250F_Rider

Posted November 18, 2004 - 04:56 AM

#8

the tube pushes air out when the piston goes down. It pulls air (and whatever is floating nearby) when the piston goes up.

If you ever stall your bike in a stream or whatever, do not kick it to restart it if the vent tube is underwater. It will absolutely suck water into the engine.

  • Satch0922

Posted November 18, 2004 - 05:26 AM

#9

The 450 can suck sand up the vent tube just as easily as it can suck water up it. Hold a dollar next to it while it's idleing some time.

Route it like this and it wont get sand in it anymore.

http://www.forumpict.../IMG_0022_1.jpg

I used one of these to mount the loose end to the boot. Just cut the nipple off of it right at that clamp groove.

http://www.forumpict.../IMG_0019_1.jpg



EXCELLENT SOLUTION!!

  • Wyatt

Posted November 18, 2004 - 06:52 AM

#10

Hmmmmmm...3rd engine on a '03 YZ450....keep finding sand in it........hmmmmm

I will call bull****

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  • John_Lorenz

Posted November 18, 2004 - 07:07 AM

#11

Or someone in his circle has it in for him and is puttind sand in the engine

  • grayracer513

Posted November 18, 2004 - 11:39 AM

#12

OK, now, let's take a look here.

The phenomena in which a YZF will draw water up the breather requires that you roll a hot engine into enough water to submerge at least the bottom of the tube and shut off or stall the engine. Then, as the engine cools, the contraction of the air inside the crankcases will create a vacuum that pulls water up the breather.

In operation, the bulk of the flow is, as stated, a push-pull condition created by the piston; 450cc out on the downstroke, 450cc in on the upstroke. In addition to that, there are combustion gases that have leaked past the rings, even in the tightest engines. These provide a continuous increase in the total gases in the crankcase and must be vented to the outside, so they at least bias the net airflow in the breather tube to the outward, with the result that more goes out than comes in.

The factory breather tube has less volume than the engine displacement, even in a 250F, so IF the crankcase pumping activity of the were 100% efficient, air from the outside would be inside the engine on each upstroke. Fortunately, it isn't even close to 30% efficient in practice, if even that. Air is so compressible that any change in pressure in one area of a closed volume must spread like a wave to reach a balance with the rest of that volume. The piston is moving so rapidly, even at an idle, that the pressure changes that occur directly under it are never matched anywhere else in the crankcase. There simply isn't time to pump 450cc of air into the crankcase, up through the chain housing and cylinder vent ports, into the cam box, out through the convoluted baffling, and all the way down the tube, before the next upstroke starts lowering the crankcase pressure again.

Let's put it this way, the engine end of the inside of my breather tubes never have any dirt in them.

When routing the hose to the airbox, you are not really putting the open end in any cleaner environment than it was in previously. (Pretty nasty in there, usually) Plus, you are shortening it, which reduces the seperation between engine and atmoshere, and running in on the horizontal, making it unnecessary to lift dirt particles to transport them. This will certainly avoid water being picked up unless it's above the carb, but it doesn't do much about fine dust unless the hose is routed to the airboot, on the "clean side" of the air filter. You could end up with a little oil in the intake that way, though. An alternative would be to route to the airbox and add a small filter to the end of the hose.

  • YZ250F_Rider

Posted November 18, 2004 - 11:59 AM

#13

A couple of comments.

1: Tell your explanation to the guys that have sucked up water in the bike. I'll take their word for it.

2: hold a dollar up to the vent tube. It will pull it flush against the tube just as easily as it pushes it away.

3: You do realize the tube is terminated in the clean air part of the boot right? It only sees filtered air routed like I have shown.

  • grayracer513

Posted November 18, 2004 - 12:27 PM

#14

So, it does terminate on the engine side? I couldn't tell from the picture exactly. Well, then, as I said, that takes care of the dirt issue. :cry:

Do you find much in the way of breather oil inside the airboot?

As far as the rest, I pretty much stand by it. As I said, I never find any grit the engine end of my breather hose, and I ride in sand about half of the time. Besides, San Diego County is where dust was invented.

As far as water goes, there's not much call for fording streams hereabouts, so I know mostly what I read here. If you're talking 2 and half feet of water for a long time at low speeds, then I can see it might be possible. Most of the accounts I see here involve engines stalled while submerged.

  • YZ250F_Rider

Posted November 18, 2004 - 12:36 PM

#15

I cant say that I have noticed any oil film inside the boot. They have always been dry to the touch.

  • grayracer513

Posted November 18, 2004 - 12:47 PM

#16

I cant say that I have noticed any oil film inside the boot. They have always been dry to the touch.


In that case, I'd say it's a four-star setup.
:cry: :cry: :cry: :cry:

  • curtains23

Posted November 18, 2004 - 01:14 PM

#17

Are you sure its sand, take the filter out and wash in fuel then filter the fuel in a coffee filter paper, I think it may be metal from the gear box, do you change gear with out the clutch as this can accelerate the wear, good luck

CURTAINS23

  • 173

Posted November 18, 2004 - 02:52 PM

#18

If you've gone threw 3 engines possibly you've melted a piston. we rebuilt a yzf quad this summer that appeared to have sucked sand into the motor but upon closer inspection it turned out to be melted aluminum it was all over on top of the piston and in the head. Maybe it got into the rest of your motor I'd change the oil very often and see if it seems to dissipate

  • Dolce_Grappa

Posted November 18, 2004 - 05:04 PM

#19

Has your frame ever been sandblasted and repainted?

  • Satch0922

Posted November 18, 2004 - 06:52 PM

#20

Has your frame ever been sandblasted and repainted?


DING DING DING DING >...folks we have a winner I think! Sounds like the most obvious (and overlooked) explaination.





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