GS/Dakar Airbox and Filter FAQ

compiled & edited by Kristian #562; Scott, ID, #1244
Please read the Disclaimer before attempting any work in this FAQ.
Last Updated: 30 December 2006, by Winter #1935

• Introduction
• GS Airfilter and Cleaning
  • Where is the Air Filter on the GS and How do I clean it?
  • GS Airfilter Installation Trick
• Questions
  • What is the Airbox drain tube for?
  • Where is the Airbox drain tube?
  • Oil in GS/Dakar Airbox
  • What's the Square Sponge in the K&N Filter?
  • Rubber Grommet/Insert Pulled Out of or Rotates in the Airbox?
  • How do I remove the Air Temperature Sensor (ATS)?
  • K&N filters: more airflow but not as efficient - an oxymoron?
  • Where does the K& filter insert go?
  • What happes if I strip the airbox screws?
  • Air filter sucked in?

For other related FAQs:

• For Aftermarket Airfilters and Opinions see the Classic Air Filter FAQ
• For other Performance comments see the Performance Mods FAQ
• Snorkel / Airbox modifications FAQ

The airbox and air filter play an important role on your fuel injected F650. The airbox helps to reduce the noise generated by your engine, but more importantly filters the air - i.e. removing dirt particles. On fuel injected models the airbox snorkle (the front part) contains a sensor that measures the flow of air into the engine. This is then used in calculations for the Fuel Injection system.

1. Remove the RHS "Faux Tank" Cover.
2. Remove the connecting Flange (the strip around the Airbox) connecting the "Nosing" or "Snorkel" to the rest of it.
3. Pull off the Front Nosing i.e. the Snorkel.
4. Remove the Filter.
5. Clean with a Vacuum Cleaner and a Soft Brush & Replace.

Note:

• The Air Filter is a PAPER ELEMENT. If it gets really wet, like you drove through a stream, it can disintegrate and go into your engine. Great Design.
• Some Snorkel Modifiers have complained of water getting into the Airfilter via. the enlarged Snorkel, in the rain.
• Being a paper filter, you have to clean it, or, at the 20,000km/12,000mile service interval, replace it. If you operate in a lot of dirt, perhaps even sooner.

• Installation of the GS/Dakar Air Filter is a tight fit. This trick has been suggested by many people. This picture and hint was provided by Sadlsor
• Cut any convenient piece of thin plastic, so that it is slightly larger than the rubber seal but will still fit in the grooves of the airbox. (See image on right)

What is the Air box drain tube for?

• The airbox gets gas, oil and sometimes condensation in it. Various poor conditions may have oil, water and gas flooding into the drain box, and thus the tube is there to drain it from the bottom. Normal airbox goo is a little water, some oil and a touch of gasoline from stopping your motor. So if your drain tap is busted, that stuff will just drip all over the bike instead of being routed into the tube.

Where is the Airbox drain tube?

• Your Airbox drain is wire tied to a wire in the spark plug area. It has a plug in the end. You can pull the hose down to make it easier to deal with, remove the plug, and drain the box. It may take a moment. The airbox also can fill with water when ridden in heavy rain. Be sure to put the plug back. It is the Plug at the end of the Tube marked GREEN in these Photos (Thanks to Seacuke). The nipple (marked red) is the bleed screw for the cooling system. Raymo #1173. The Tube is NOT supposed to be connected to that nipple, in case you thought something was amiss.

• There are generally two causes of oil in your airbox on a GS.
• Firstly - You have dropped your bike on its side.
• Secondly - You have overfilled the oil. It is very easy to overfill the oil on these bikes, particularly on models with the sight glass for the oil level. See the GS Oil Change FAQ.
• Also check / clean the main throttle body as oil may have attracted dirt. See the Fuel Injection FAQ.

Note:

1. The Rubber plug in the Airbox that the Upper RHS Oil Tank Bolt goes into can turn in the Rubber Grommet in the Airbox and the Brass insert is pretty thin, so don't over torque it when you do your Oil Change.
2. The other place where they use a similar arrangement is the Airbox Drain, which leaks oil past the Rubber Seal, down along the outside of the Drain Tube. Great. I couldn't tighten it any either. What's wrong with a cast Plastic Nipple like the Classic?. I've never over-filled the Oil, nor dropped the bike, so oil coming up into the Airbox is a bit of nuisance, especially with that dreadful Drain Arrangement.

A good explanation for this phenomenon is in the Classic Air Filter FAQ under " How does Oil get INTO the Airbox?"

• On a K&N Filter for a 2001 650GS, you are told to put this square sponge provided into the middle of the air cleaner unless you motor has been modified. Does anybody have experience with leaving it out or putting it in?
• I left mine in until I got the FN installed and the O2 sensor unhooked. Runs well now with that combination. Quite smooth and not a trace of surge. It also pulls well from the low 3's right on up. Leaving the plug in is probably to avoid making the bike run any leaner than it already does. The FN and O2 sensor disconnect richen things up. BradG 1002.

• Typical Problem: With a printout of the oil change FAQ in hand, I changed the oil in my 2001 Dakar this weekend. All went well enough, but I found that the rubber grommet in the airbox that the oil tank is tightened with had been torn, apparently during a previous oil change. The grommet actually slipped back into the airbox. Fortunately, the bolt was partially inside the grommet, but I had a terrible time getting the rubber grommet back in place in order to properly tighten the oil tank. Question--How easy is it to replace this grommet with the threaded brass insert? I assume that it would involve removing the snorkel and reaching inside the airbox.
• Solution 1: I replaced mine after a hard left-side fall that caused the grommet to rip out. You have to have one hand up inside the air box just to make sure you don't drop anything down the intake that sits directly below this nut/grommet assembly. Better yet put a small cloth over the intake while you are working. IMHO this grommet is a very poor design. With just the two lugs on the bottom of the oil tank and this flimsy grommet on top, any hard fall on the left side of the bike will break the lugs off of the oil tank. Just one of the reasons I stopped treating this bike like a dirt bike (I love this bike and I want it to last and be in good shape and not have all these bent/broken/welded parts). Rod CO '02F650GS
• Solution 2: I used some black RTV sealant to seal the grommet in place. It both seals and will keep it secure when the bolt is removed for future maintenance. Raymo #1173, Chicago, 2001 F650GSA

Feedback

• If you don't "remove" the oil tank you can't louse up the connection. A distinct possibility given the construction. I just let the bike lean to the left on the sidestand (Dakar) and let the oil drain into a pan that way. Removing the oil tank to change the oil is a mistake, IMHO. echo
• I use a simple fluid pump (about $6) to empty the tank of oil for oil changes. But to service the valves you need to pull it any way. You can't completely avoid removing it so a good fix is worthwhile. Brad, N. CA., 2001 F650GS - Inmate #1002

1. Remove the RHS Cover.
2. Locate the ATS under the Airbox about 1/3 of the way back from the front of the Snorkel
3. 
4. Unclip the Wire Spring Clip First (Circled GREEN). Use a wide-Blade Screwdriver or a normal cutlery knife to prise out the spring clip. There is not enough slack in the wires to undo the sensor without doing this first.
5. Then Unclip the Plastic Spring Clip (Circled RED).
6. 
7. Extract the sensor, which is normally housed in the Airbox.
8. This picture shows the Air Temp. Sensor STILL in the Airbox.
9. 
10. Extra Photos from Simpco

K&N filters: more air flow but not as efficient - an oxymoron?

• If the filter permits more air-low then it's either got to be less dense or have larger diameter holes in the filter material, which in turn permits some fine (very fine) particles to pass through, which the original standard filter would have collected. Trevor #999 Bristol, UK.

Where does the K&N filter insert go?

• If your FI system has not been modified, the read foam block should be left inside the actual filter. If you have added a FI box such as a PowerCommander, you may not need the red foam - please refer to the K&N instructions.

What happens if I strip the airbox screws?

• I was replacing the air filter last night on my GS and tightened the lower of the two self-tapping screws that retain the plastic collar (cover?) in place. (That skinny U-shaped piece.) As I tightened it I got that sick feeling I was turning the lower screw and it wasn't biting any more... sure enough, my fears were confirmed. I had my air filter changed at the dealer last time during a service, and it looks like they may have run into the same thing and filled it with Loctite or something. Anyone else run into this? Ideas??? TeamGS
• 2 options. 1 dont worry about it, or 2 try a bigger screw. gsatlanta
• Forgive me if you have already tried the obvious but, first remove the snorkel and the clamp and try the screw by itself. Use the long, skinny allen wrench supplied in the oem tool kit. It is impossible to see if the wrench is mated to the screw properly when it is in the clamp hole and unlike all the other screws the torx wrench won't fit, so that may be the problem. Then, if the hole is truly reemed, you can either use a bigger screw as mentioned or fill the hole with (?-maybe someone else has a good recommendation) and re-drill it. SScratch
• A third idea might be to slightly melt the stripped hole, maybe using a hot nail that is smaller than the hole (this of course assumes the threads ARE plastic). Anyhow, the idea would be to essentially deform the plastic, shrinking the hole. Hmmm, maybe a heat gun would swell it shut too. If successful, you could then use the original screw and self-tap new threads when re-installed. In any event, if this doesn't work . . . use a bigger screw. Scott, ID #1244
• A fourth option would be to slip a thin sliver of plastic into the hole, then thread the old screw into it. This works pretty good for wood holes that are stripped out. Not that I've ever done THAT with the tuning machine holes on a $4,000 guitar . . . If the wood sliver is glued into the hole then the fix is permanent. Some epoxy might work the same way here, though it is difficult to get most glues to stick to polyethylene plastics, I think. Scott, ID #1244

Air filter sucked in?

• I have owned my Dakar for 4 months 5500 miles, and lately I Noticed a little bit more vibration coming from the engine. I also noticed the bike stalling more often. So I decided to investigate and found my air filter was sucked into the air box leaving the airway unfiltered... for who knows how long. I just wanted to warn you all about the cheap/ flimsy air filters in this bike. Now I am wondering how much damage this could have done?! ronzep
• That's really something that it got sucked in there. The only thing that I can think of is that when the snorkle was fitted that it somehow interfered with the airfilter seating. (Unless you have some insight into some other problem with the airfilter.) I've had to fit and re-fit the snorkle-airbox a few times before to get it right. As far as worry about damage from the unfiltered air, I wouldn't sweat it. If it's running fine now, ride it. Citizen