F650GS/Dakar Snorkle FAQ

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

• Introduction
• Modifications
  • Cutting the Intake Snorkel. Where to cut.
  • Snorkel Mod 2
  • Snorkel Mod 3
• Comments
  • Comments on Performance
  • Comments on Water Getting into it

For other related FAQs:

• GS/Dakar Air Filter FAQ
• Fuel Nanny FAQ
• Dyno Runs FAQ

Modifying your airbox snorkel may result in an increase in performance from your bike. Some people experience the increase in performance, others are unsure, and yet others think there is no noticable increase. One purpose of the airbox is to reduce the noise emitted from your engine, so cutting the snorkel will increase the noise from your bike. Also, with an increase in airflow, the BMS-C / Fuel Injection unit may increase the fuel - possibly resulting in higher fuel consumption.

BradG#1002 et al

• Refer to http://www.touratech-usa.com/f650rr_instl/english/index.html
• Steps 56,172 and 173. I used a Dremel to cut and smooth, worked well. Sounds throaty, now just need a Staintune.
  • Step 56 Disassemble the intake. Remove the plug from the temperature sensor. Remove the two screws and pull outward on the clip that connects the two halves of the air cleaner housing together. Pull outward on the intake and then back to remove.
  • Step 171 The air cleaner housing (airbox) can be remounted onto the throttle body/butterfly housing. The two new aluminum mounting bolts are used to secure the airbox to the cross member mount. (6mm hex). These bolts are tightened to 4-6 ft/lbs.
  • Step 172 The intake housing is now cut off 10mm past the temperature sensor. After cutting the intake the edge can be smoothed using a file or knife blade.
• There is also one on the Techlusion site. http://www.techlusion.com/F650.htm. Scroll down the page through the Fuel Nanny install information to where it says Air Box
• You should not expect a lot of performance out of this alone. The idea is to get more air (and fuel) to flow through the engine to gain power. Just providing more air to the same filter and exhaust is only part of the equation. The bikes computer will adapt to the improvement but you have no control over it without something like a Fuel Nanny or knowing how to remap the bike yourself. You'll probably just end up with more induction noise which may be to your liking. The cost to replace the snorkel is about $40 I think.

by Johan Rodskog

• I have done a snorkel mod that avoids cutting the snorkel (and all the rain/water problem associated with it) I went to the hardware store and bought 3 small round air vents (27mm in diameter). I then used my drill with a hole-saw attachment to drill three holes on the side of the snorkel right in front of the air filter (holes facing inwards, towards the frame/battery). The air vents "snap" into place for a tight fit (I did use some silicone around the edges to prevent vibrations). I estimate that with the new vents, twice as much air reaches the filter, the vents are protected from direct water and rain (and can easily be temporarily duct taped over in extreme conditions.). The vents effectively prevent small rocks/leaves/etc from entering the airbox.
• I am heading off on a 3 week trip to the Simpson Desert here in Australia tomorrow, but I'll send pics when I get back.

by Kristian #562

• Slight 3cm x 2 cm Cut-out at inside of Intake. Noticeable increase in low-end, Throttle Roll-on Power just from the Small Snorkel Mod.
  

• Refer http://www.vmar.com/touratech/f650/english/index.html The intake housing is now cut off 10mm past the temperature sensor. After cutting the intake the edge can be smoothed using a file or knife blade. DavidHPark#711
• Parks suggests to cut the snorkel just in front of the temp sensor mounted on the bottom of the snorkel. Before you do this I would suggest simply removing the snorkel entirely from the bike. to do this you must disconnect the temp sensor and plug it back into the bike and simply zip tie it to the frame or the wiring harness running along that area. This will allow you to try the modification and still allow you to go back to stock if you do not the like the increase in intake NOISE!!. For me the extra noise was far out weighed by the air under the front wheel in 1st gear, cant wait for that K&N and the fuel nanny they say that lifts the wheel clean through 2nd. Brian#834
• The snorkel modification is completely cutting off the front section, about 1.5 in front of the air sensor. I cut a long hole the width of the front section, on the bottom, to maintain the front tip that supports the snorkel assembly. I also run a K&N filter with a Remus exhaust. Not too loud, and not too quite. My wife rides this bike and gets great MPG. I ride it hard and get much lower MPG. Iceman #975
• I have put the Remus on my GS (and adjusted the air intake snorkel). It fits really well and sound brilliant. As a bi-product my fuel economy has got better:-} PJ
• Staintune on 02 F650 GS. No problem with the FI. While you're at it chop the airbox snorkel down to size. Your bike will thank you with better breathing. If you want to do the whole bit put on a digital Fuel Nanny and dyno/CO2 tune the bike. You'll be amazed at the difference all three changes together will make. DavidHPark#711
• If you want to go back to stock, the Intake Snorkel cost $ 24.79 US Dollars. JV.
• I've not cut the snorkel, but I've drilled 4 holes (10mm diameter) in the midway between air temp sensor and opening. My intention was only to reduce the bad noise. I've not noticed a change in power but I prefer the sound, more virile now. Jean Richard.
• Significant and noticeable power increase, especially mid-range. Top speed before = 94.x After = 99.3 (GPS measured). The before/after also included the R1200C injector and a couple of holes in the snorkel, but I think it was mostly the can.
• In my case there was a noticable difference. It was louder, but I did not find it too bad and a new Adventurepipe in the new year will cover up the sound, ha-ha. I noticed a slight increase in performance even taking into consideration the psychological effect of "louder is faster" There was absolutely no doubt that the bike now wheelies a lot easier. The "noise makes it seem faster effect" cannot account for the fact that the front end keeps popping off the ground now so I would say the performance increase is for real. It's not dramatic, not like I hit a Nox switch or something, but it can be felt nonetheless. I think it was worth the effort on my bike, YMMV of course. Bario
• I have read the FAQ's about this for the F650 GS, I like the mod with the vents added. I have taken the snorkle off completely as suggested and zip tied the sensor at the air filter and went for a ride. (louder !!!) faster, more torque????? At first I thought so, but then put the snorkle back on (quieter!!!) tried to gage is improvement was lost again? liddell
• I tried the same test as well and I noticed no more power with the snorkel removed. I did however notice (subtle) improvment from unplugging the O2 sensor on the exhaust and the projected tip plug. After doing roll on tests against stock bikes (mine also has a staintune) there isn't much improvement to be had. blair.r #1529

• Don't you get water in the motor with the air intake cut. I get a good deal with the stock intake. Or maybe you guys don't ride in the rain. I think the intake is about all I can hear when riding my Dakar. I see where people may recommend you cutting the intake but if one rides in the rain you may wish to rethink that. I find when I drain the Airfilter though its drain I get water so even with the stock intake water gets to the filter. I ride in a lot of rain. You may wish to drain the air box if you have not already done so. I do it regularly. You will get both oil and water. Supertech
• I have to agree with Supertech. If you do ride in wet country the air box does fill up with water. I found this out the hard way, living in the north we get rain & rain!
  Someone wanted to know where the drain for the air box is. The drain is on the right side, small rubber hose coming down off the air box. Rick #815
• That would be my concern also. The first time I changed my air filter I noticed it was stained. Looking into the airbox I thought I had a serious amount of oil in there. After draining it turned out to be a thin film of oil on top of about a 1/3 cup of water. This was after a recent 2-3 hour ride in heavy rain, much of it on freeways with moderate to heavy traffic - you know, like riding through a car wash. And I have since modified my snorkel with a couple of 1 holes. I haven't ridden in really heavy rain for that long a period since then, though I have ridden in heavy rain. I've not had that much water in the airbox since, either. Soooo, I'm beginning to think that the snorkel in stock configuration may actually suck more water than a modified one. The air is being drawn into the stock opening at a higher velocity than an effectively larger opening for a given volume of air. That said, I still think the snorkel mod David/Techlusion are talking about looks pretty radical. There is still a lot of road spray that gets thrown up from the front tire into that area. Mike639
• It doesn't rain too much in the desert during a Rallye but it did so at this years Dakar both in the beginning of the Rallye all throughout Europe and at the end from Kiffa to Dakar. The Touratech bikes with the modified snorkel ran fine in those conditions. People are running Touratech bikes with snorkel for Enduros as well as it can be wet and muddy. I wouldn't worry about going back to stock as it's really better without the dumb snorkel. Just keep your cut away part and superglue it back if you want the engine to perform poorly due to lack of O2. As for H2O in the airbox, not from rain, only if you dump the bike in the river when crossing. DavidHPark #711
• One more thing! Inside the airbox , is created a large suction from motor running, so the air breather hose leading into air box probably sucks oil right on into the box. Even from a non-overfilled bike. Mine did have some oil in there from early days, but the rerouting of breather hose eliminated it. Hope we never get smog inspections in California. If so, I'll have to go back and replace everything to stock. Randy748