Sand under left hand PV cover!!!

[highspeedsteel]

Hi put new rings in my bike tonight. It was the 1st time I have had any of the left hand Power valve cover off and when I was undoing the bolt that holds the barrel, under the cover I noticed it was coated in sand!!
The only way I can see it has got in is through the drain tube, I thought of getting an inline filter like I have for the fuel line and putting on there but I don't think it will let the oil that seeps out escape. So any ideas? Just had an idea while writing this, a section of low density foam should stop it but would probably get blocked and need cleaning eventually.

Has anybody else ever noticed this? I don't think the sand had got any further because it was stuck to the oil around the bolt but seems like a bad place for sand to get!!

Ideas anyone??

By the way most of my riding is in sandy conditions.

Cheers

[GMP]

Carried in by water? Stall in a water crossing?

[highspeedsteel]

Haven't stalled in a water crossing but I have done some very wet rides. So I guess that's a possibility. I guess washing the bike could cause this, although I don't use very high pressure water I guess it could be enough to force a little water/dirt up the tube. I'm going to try and think of a way of stopping anything getting up there while letting the oil still escape.

Cheers

[GMP]

Honestly I've never saw that happen in 7 years with 3 GGs. I've been through deep water too, but never stalled there. Ridden many sandy/dusty enduros also. How is the line routed? You can plug the line and drain it manually after riding as well, My bikes with the line tied off.

[gasgasman]

Sure it ain't carbon deposits?

My PV drain is zip tied like Glenn said.
Drain it while at home........so you don't kill the Sabine Shiner living in the streams.

[highspeedsteel]

Not Carbon deposits it is sand.

The line is routed down the back of the frame tube that is just below (this is how it came) it has a zip tie holding it but its loose. I have thought about squashing it down to stop the oil dribbling out on the back of my pick-up after a ride.
Thanks for the info

[gasgasman]

It may be possible that the exhaust pulses is creating a "vacuum" that can suck dirt into the power valve chamber.

Maybe I need to check mine.
My bike has had a VERY wet life.

[Boomhauer]

Originally Posted by gasgasman

It may be possible that the exhaust pulses is creating a "vacuum" that can suck dirt into the power valve chamber.

Maybe I need to check mine.
My bike has had a VERY wet life.

Since you bought that new bike all it has done is rain! It's all your fault damn it!

[GMP]

It may be possible that the exhaust pulses is creating a "vacuum" that can suck dirt into the power valve chamber.

This is a good question and worth checking out. When the PV chamber is open to the port (low RPM), and the piston opens the port, perhaps there is an intial verturi effect where a negative pressure exists for a short time before the pressure pulse is reflected back from the pipe. Thoughts?? Funny I have never seen anything but a coating of spooge in there, with an open vent line.

[rider01]

Maybe the line sould be routed back to the airbox , that way if it sucks air it'll be clean filtered air . When I had my YZ400 I read of a lot of the 4 stroke guys doing this mod .