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Damn... dirt behind the air filter

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So..yesterday I went to change & clean the air filters in both bikes. I found that "I" didn't get the air filter seated right on my 04 300...for some reason. When I took it off there want caked on dirt between the filter and the air box where it seats. I pulled everything apart (air box/sub-frame) and washed it all clean. I then remove the exhaust pipe and reed cage to look to see how much dirt really got in there. I run my fingre inside and it felt gritty. I wash my hands good and feel again and this time it's not so bad. Piston doesn't look too bad for 25 to 28 hours...

What do you think I should do??? Ride it, or rebuild it..... This bike has less than 60 hours total. I don't gt to ride as much aftr getting sick last yesr...:thumbsup:

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So..yesterday I went to change & clean the air filters in both bikes. I found that "I" didn't get the air filter seated right on my 04 300...for some reason. When I took it off there want caked on dirt between the filter and the air box where it seats. I pulled everything apart (air box/sub-frame) and washed it all clean. I then remove the exhaust pipe and reed cage to look to see how much dirt really got in there. I run my fingre inside and it felt gritty. I wash my hands good and feel again and this time it's not so bad. Piston doesn't look too bad for 25 to 28 hours...

What do you think I should do??? Ride it, or rebuild it..... This bike has less than 60 hours total. I don't gt to ride as much aftr getting sick last yesr...:thumbsup:

Maybe do a compression test?

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well if you think it got SOME dirt in it then it would be prudent to clean it out. You could pour some gas in the cyl work the crank around and tip it over and pour it out, you could remove the top end and do the same with better results, or you could take the top end off and rebuild it and the lower end as well. I would opt for pour some gas in it and ride IF the dirt isnt too bad. The bikes are tuff.

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Is that something you made yourself or bought? Effective??? I hate the amount of dirt I get inside the box, far too much. Thanks.

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I cut it myself from one sheet of course UNI filter foam. It doesn't slow down the air at all. It works very well and stops the bulk of dirt from getting in. I like to keep my filter very clean and with this I can go much further between cleanings. The bike has been completely caked in mud before and barely anything got into the air box. It does well with very fine dust but for that it should be oiled or the more dense UNI foam could be used.

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Is that one side that just lays in the box against the door/filter or half of a flap that folds over the top too?

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Here's the other picture I have. Basically it's one sheet that lays over the top and side of the air box. I trimmed it a bit and then it's tucked in so to not move around.

Here's the link to the filter foam:

BF2 12"x24"x3/8" 30 PPI coarse foam

http://www.unifilter.com/online%20catalog/accessories.html

If you get the foam home, take the seat and side cover off, and lay the foam over the opening, you'll see how it's sized perfectly.

airbox.jpg

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Thanks, sorry to redirect the thread guys, that is a great mod tip though!:thumbsup:

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very nice where can i get that foam? i have bought the moose foam but its not big enough to cover the to too

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Any shop could order it through their distributor.

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Here's the other picture I have. Basically it's one sheet that lays over the top and side of the air box. I trimmed it a bit and then it's tucked in so to not move around.

Here's the link to the filter foam:

BF2 12"x24"x3/8" 30 PPI coarse foam

http://www.unifilter.com/online%20catalog/accessories.html

If you get the foam home, take the seat and side cover off, and lay the foam over the opening, you'll see how it's sized perfectly.

airbox.jpg

Just thought I resurect this thread. I've got the Uni BF-2 bulk Coarse air filter sheet on order and it should be here tomorrow. I'm anxious to see how well it filters out the majority of crap that coats my twin air.

I don't plan on oiling this though at first. It seems that would leave an awful sticky mess to clean. I figure if this foam will cover the parts where there is a gap between the seat and the side plastics, then half the battle will be won. Last night I used silicone to seal all the seams under the fender in an attempt to eliminate the muddy water from getting into the airbox. I've yet to test it out, hopefully I can test it this weekend.

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it turns out the shop got my order in today and I installed the foam tonight. Mine doesn't look as nice as sfrdr'sm but I suspect it is adequate to close off those horrendous gaps between the seat and the side plastics. I also supsect that my caulking of the under fender seams should keep out the muddy water that I'm sure to encounter on the trails this coming Saturday. The forecast calls for torrential rains from now untilt then and even on Saturday. So I doubt I'll be able to test the powder stopping ability of the "pre-filter"m but at least I can test the sealing of the fender area.

I'm hoping that this foam thing will be better and cheaper than filter skins over the long haul.

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FYI.....I ended up removing the cylinder for a good cleaning. I did not find any dirt of any kind. New Wossner piston kit just because it opened up. Good to go....

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That's a neat idea, but I basically achieve the same thing with black duct tape and a couple pieces of car wash sponge. I RTV'd my airbox to rear fender one time. It made getting the fender off hard and the sealer gets on the subframe.

I worry less about dust as I do mud and muddy water.

I do like the look of the Uni foam. Looks like ya could even sell it as a finished product it's so neat. :thumbsup:

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it turns out the shop got my order in today and I installed the foam tonight. Mine doesn't look as nice as sfrdr'sm but I suspect it is adequate to close off those horrendous gaps between the seat and the side plastics. I also supsect that my caulking of the under fender seams should keep out the muddy water that I'm sure to encounter on the trails this coming Saturday. The forecast calls for torrential rains from now untilt then and even on Saturday. So I doubt I'll be able to test the powder stopping ability of the "pre-filter"m but at least I can test the sealing of the fender area.

I'm hoping that this foam thing will be better and cheaper than filter skins over the long haul.

What did you do with the drain hole in the bottom corner of the air box? With the lousy design of this air box, sooner or later water's going to get in. Not having a drain hole in the bottom scares me. My KLX250S has a sealed air box w/snorkel that won't let any water in until the depth of the water (stream crossing) is up to the gas tank petcock. What's up with KTM?:)

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What did you do with the drain hole in the bottom corner of the air box? With the lousy design of this air box, sooner or later water's going to get in. Not having a drain hole in the bottom scares me. My KLX250S has a sealed air box w/snorkel that won't let any water in until the depth of the water (stream crossing) is up to the gas tank petcock. What's up with KTM?:)

I didn't mess with the drain hole. Everything I attended to was either at the top or on the outside of the rear fender.

I would never plug the drain hole. I'm just trying to get it to where I don't even see any evidence of the muddy soup that seems to find it's way into the airbox area.

I'll be placing some black duct tape over the seams under the fender area too, just for good measure.

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Well, I went out today and we didn't get the rain I ws hoping for, but the pre filter got a pretty good workout. The trails were pretty dusty and the main filter looks nice and clean. I rode 75 miles two weeks ago and 35 miles today on the same filter and it looks no worse than it did when I started. the 75 mile ride was after a nice rain, so no dust.

So if you're looking to get more uses out of your air filter without having to go through the dirty and sticky process of cleaning it, do yourself a favor and get one of those Uni BF-2 Bulk filters and cut it to fit.

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