Here is my take on that pesky air filter letting dirt get by................ Just add a pre filter! All you have to do is get some Uni Filter material and cut to size This pre filter gets inserted in FRONT of the stock filter, it does not replace it!! You just slip it in the rectangular opening on the intake air side of the air box, then put the stock filter back in. Sorry for the crappy pic You are looking at the cavity were the stock filter goes On the left is the green pre filter on the intake side Clear as mud I hope This mod may cut down on some air flow but my bike seems to run just fine! Heck it might even richen up the mixture a tad! Thoughts and comments good or bad welcome Thanks Glen P.S. Do not forget to oil the pre filter before instalation
Good idea my lawn mower has prefilters made of foam that lay over the paper element too......I wonder ?????
This is hard to see in the photo but it is held in place by the partition that forms the rectangular opening in front of the stock filter, where the air comes in. It is easier to remove your filter and have a look in the air box then you will understand.
Don't use K&N filter oil on foam filters, it's not the right stuff for the job. Use an oil for foam filters (Uni, No Toil, Twin Air, etc). The cloth filter oil (K&N) isn't the same stuff and even if it doesn't damage the foam, it won't stick the dirt to it as well and that dirt will just pass through. You'll want to make sure it's all evenly, but lightly coated to keep the mess down.
This is absolutely correct! The filter media I used for the pre filter is the same type of foam UNI uses for their bike specific filters and needs oil for foam filters!
If you ride a lot on dusty roads/trails you might want to make up a couple of pre-filters. I have always had a spare air filter for my dirt bikes cleaned and oiled sitting in a freezer bag. Any excess oil is free to accumulate in the bag and not in my air box. I think I'll spend some time this weekend and modify the air box and cut me a couple of TR pre-filters.
Yes, mine has a gap as well. I would think this is normal since they probably just cut a length from a long spool. Maybe a little RTV to fill it in?
Take a look at the parts manual. Its supposed to be a one piece rectangle. I found sand granules in the airbox, it was getting in under the seal and through that gap. I just crazy glued mine back together until I can get a replacement.
You will find this is on the intake sides so a well sealed filter will catch the dirt but maybe let water in if you swim it.
All good stuff, I have been working on an oiled pre filter which I have for an f800gs, sort of like a tapered Phallus, which I will push up the intake snorkel from the airbox inside so a big percentage of the dust is caught before the paper element, all of this stuffing around to satisfy the stylists and why an adventure bike has a flawed airbox design and is such a pain to replace is beyond me, I think I need a Mars bar.
Actually, I do not believe this gap would be on the intake side. The sealing surface of the filter makes it so that anything around the filter is unfiltered. This gap allows air to flow into the cavity that the filter sits in, not the intake cavity. It is a small, pinch gap, so only very dusty conditions would likely be any type of problem. Simply put RTV or weather stripping or anything to fill in the gap. Heck, maybe remove the gasket altogether and put a small bead of RTV in the groove and let dry before reassembling.
