holes in filter

Has anyone ever had a problem with holes in their filter?

I have been doing a lot of road riding and had filter skins on it so I haven't had to take it out and clean it. Yesterday I pulled it and to my dismay I seen the rear/bottom portion of the filter eaten away.Not from a mouse either. I know these bikes have backfire screens in them so something must come through the carb the wrong way. Is it possible that it is being eaten from fuel? Im not exaggerating, its bad. Completely through 2 layers of a Uni Filter. I searched and appearently I am the only one with this freak problem

The only changes to my carb is a jet kit and a smaller leak jet

The only thing I can think of that would eat a filter is either FIRE or battery acid.

and considering your bike hasnt caught fire so far....

seemingly the batteries are sealed units, unless yours has split open or done something wierd. Take your battery out and examine it closely for any leakage.....should be white residue all over the place if so.

I have experienced this problem with an old filter that was getting close to needing replacement and got a bit dry. Like you I was running on road at the time and hadn't cleaned or oiled the filter for some time. I think in this case the foam just broke up and was sucked into the engine.

dont forget cleaning it with gas tears it up real fast.

but it is very common, need to keep it oiled and clean.(lasts longer)

here are a few pics

since no one has knew what I was talking about, I dug it out of the garbage can and took a few pictures

Wacky huh?





no one?

Maybe got damaged on a sharp edge during removal or reinstallation

Backfire,are you sure the screens are there?are you the original owner?maybe someone took them out before you.

Busted Bones.Did you see the picture? You think I possibly did that installing the filter? Edward Sissorhands wouldnt have hacked the filter like that

Yes Sir Dirtrider. The screen is in there. Imagine if it wasnt?

how was that filter last cleaned?

From what I can tell, usually gravity pulls things down, by that, I mean that whatever you cleaned it with (say gas or actual "filter cleaner") didn't get rinsed out 100%, then the filter was oiled and reinstalled, the contamination (gas/cleaner) then settled at the bottom portion of the filter because it is thinner than the filter oil and will travel due to gravity, there it sat and ate away.

Remember that most of these cleaners are solvents, solvents eat oils and petroleum products.

Looks to me like whatever did it was from the outside in. Looks like it "melted" or was eaten by solvent or acid.

looks like heat damage, although ive heard some of the new bio safe oils can eat foam if left on for too long...as for backfire screens, ive been on blue 4 strokes since 99 and thats the first thing i do is replace the cage with one from a yz 2 stroke, the difference in throttle respone is amazing....ive never had a fire....maybe im just lucky

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