Air filter

[Ryan426]

Today I was going to clean and oil my air filter on my YZ 426 I bought last month. When I puuled the seat I was shoked to see a filter that crumbled when I touched it. When I bought the bike the dude told me how precise he was with maintance. I'm worried what all I sucked in to the motor. I'm surprised at how well the bike ran with it. Might explain the poping I had when I let off the gas. Looks like I won't be riding this Tuesday. ?

[husqy360]

i had 1 filter that crumbled from being in the sun for to long.

[tek_01]

That sucks hey? Similar thing happened to me... Previous owners said he cleans his filter every ride and all the usual stuff... took it home and opened it up and freaked when it was so black i couldnt see what brand it was.

You may have gotten lucky, if it was untouched than it probably didnt suck any in or it only took a little in. and a bit of foam is better than a bit of dirt IMO too lol

good luck

[02WR426Cali]

Hmmm I've never had that happen to me. I have seen very old filters do that but that's usually after they had been sitting for years. He must have used and cleaned that filter one too many times. I doubt it sucked in much at all if you still have the backfire screen in there which you should. What's the inside look like? Does it look like anything came apart and got sucked in?

[mxdirtking]

The popping when you let off could be the jetting of the bike. My bike did the same thing and it wasn't even jetted when i bought it with a pipe on it so that could be an idea.

[JandJ07]

Might explain the poping I had when I let off the gas.

https://www.thumpertalk.com/forum/showthread.php?p=3710599#post3710599

Grayracer has a good explanation for your decel popping in this post.

As far as your foam filter crumbling...I have seen that several times simply for extreme lack of maint. Over time the foam simply deteriorates. I would be highly inclined to check the rest of the bike over for proper maint. If the air filter was not...then unfortunately the rest of the bike probably wasn't either.

[Ryan426]

Got the air box all cleaned out and looks like nothing got passed the filter. Now must wait till dealer opens tommrow. Most likely they will have to order me one since none of the local dealers in my area seem to stock what I need. Or stock any thing for that mater!

[642MX]

Got the air box all cleaned out and looks like nothing got passed the filter. Now must wait till dealer opens tommrow. Most likely they will have to order me one since none of the local dealers in my area seem to stock what I need. Or stock any thing for that mater!

They should have it considering the filter fits just about every YZ smoker and YZF 4 stroke. The RM250 uses the same filter too (might try a zuki dealer is your Yamaha dealer doesn't have one).