Hi, I put together this spreadsheet because I thought there might be others who wanted to do add an aftermarket pipe, or add some other performance modifications. I know I needed it when I was doing mine. It's always easier to point to a FAQ too. Note this is primarily Exhaust/Airbox/Carb related, with some Clutch & Timing information. It does not cover Suspension or anything else. 
A Big Thanks to all the Contributors, especially Richard230, Harl, Fede, Craig, Todd, Flash, Walter and Mark58 the latter who wrote the following oh-so-true statement: "I don't know your riding background, but if you're like the majority of folks, you'd be far better off taking an advanced riding school than spending a couple mortgage payments worth on aftermarket exhausts and trick performance parts. Most folks don't use half of what they've already got. I realize this is heresy and that there's a time-honored tradition of fiddling with your ride to personalize it, but a lot of times those bikes that have been "upgraded" are really messed up. If you know what you're doing, then a freer flowing pipe, jet kit, airbox mods and so forth can eke out a few more HP and smooth things out a bit, but the dollar spent to HP gained ratio is pretty high and the effect lasts until you get tired of your current bike. Good riding instruction lasts forever. You could also spend the money on good riding apparel. Your call."
But if you're going to do it anyway, I hope this helps you out. ! Rgds, Kristian #562
F650 Exhaust Rejet/Injector Register 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17  
Name Chain Gang Member # F650/ F650ST/ F650 GS Year, Mileage Airbox Modifications: e.g. Organ Pipe Holes Drilled Out and/or Snorkel Removed or Additional Cutouts aka Ron Woods. Exhaust Pipe Modifications: e.g. Stock or Arrow or Remus or Staintune or Laser or Micron or D&D or Other (Baffle in or out) Air Filter. E.g. Stock (Foam) or K&N or Other Main Jet Size & Source: e.g. Stock (#132.5) or Sudco #137.5 or Dynojet #140 Pilot Jet Size & Source: e.g. Stock (#41.2) or Factory #45 Needle Clip Location: e.g. Stock (4th from Top - Blunt End) or Factory (2nd from Top) Float Bowl Level: e.g. Stock or 15mm or Not Modified # Turns Idle Screw from Lightly bottomed out: e.g. Stock 4 turns or 3 turns or 2.5 turns Injector Modifications: e.g. Replaced with R1200C injector FI Software Mapping Revision Elevation: e.g. Sea Level Timing Modifications: e.g. Ron Woods Ignition Advance Key EPD Cannister "Fell off". Yes/No. Average Mileage Around Town/Highway since Modifications Remarks/Recommendations #1 Remarks/Recommendations #2 Remarks/Recommendations #3
Richard #230 F650 1997,  22,300 Miles Stock Staintune Slip-on, Baffle left in Stock Stock Stock Stock Stock 4 turns out. N/A N/A Sea Level (SF) N/.A Yes. 52-60 I installed a Staintune exhaust (sounds fine, only a little louder than stock) with no baffle modifications, jetting, filter or air-box changes.  The bike seems to have a bit more mid-range power, but less top-end power now.  I have my idle air-screws set at 4 turns out and that works well at low throttle and when starting (stock, it used to need full choke even in 90 degree heat). I lost the canister and now have full access to my fuel, instead of only 3.8 gallons, max. My chain wore out at 12,000 miles and the steering head bearings became notchy around 8000 miles and were replaced under warranty. I have all of my stock sprockets and they still look like new.  I have no intention of ever replacing them. I have installed a MAP 320mm front brake rotor and Galfer steel braided front brake line.  I am currently using DP brake pads. My chain is a DID VM and is holding up well.  I oil my chain every 250 miles. I like my Staintune because of its looks, because it is much easier to clean and because it runs cooler than the stock exhaust. The stock bike has enough speed for my purposes.    
Craig #325 F650 1999 , 22,000 Miles Organ pipes drilled out. Staintune Slip-on, Baffle left in K&N filter. #140 Factory #45 from Factory Factory needles #2 clip setting 15 mm 3 turns out. N/A N/A Sea Level N/.A Yes. 40  I tried riding with the snorkel removed, too loud for me. The factory slide springs I found are too soft and cause a surge at 3600-4000 rpm's. Reinstalled the stock springs. With the #45 pilot jets I have much better throttle response and power from idle to 1/4 throttle. By the way I just installed an Ohilns shock. That thing is great. If I had to do it over the shock would have been first. 2 hours to install and the improvement is out of this world.    
Walter #466 F650 1999 , 25,000 miles. Snorkel removed, organ pipes drilled out and removed. Full Ron Woods exhaust pipe (headers & muffler). K&N filter. Dynojet recommended kit (I believe 138 main). Stock Dynojet needle, blunt, 2nd from top. Stock 4 turns out. N/A N/A 50 ft (Sacramento). Woods ignition advance. Yes. 45-50 Exhaust is louder than Staintune with baffle in, quieter than without. Maximum performance gain from new exhaust.  Performance is very good, although runs hot (lean), I weigh 270lb and the bike will stand straight up from pure throttle, no tricks.  Down side- On my 4th chain, 3rd front sprocket, and 2nd rear sprocket, as it stretches the chain and pulls the teeth on the sprockets. I have sitting in my garage the rest of the Woods kit (carbs, piston, valve springs, and new cams) and am waiting for new valves and race clutch springs and the time to install all mentioned.  The bike is an ongoing project and will more than likely never be finished, I absolutely love the bike. Additionally, a list like this would be great for all aspects of the bike (suspension, GPS, mirrors, windscreen, etc) and I would be willing to contribute all that I have done.    
Kristian (Try #1) #562 F650 1996/1997, 24850 Miles. Bike has all same stock Carb Jets/Needles as US 1997 onward Model. Organ pipes drilled out but not removed. Staintune Slip-on, Baffle left in Stock #137.5 Local Dealer #45 from Sudco Stock Needle 3rd (Middle) clip from Top Stock, but checked and modified back to stock - it was out 3 turns out. N/A N/A Sea Level (Hong Kong) Tried Woods ignition advance, but Team Pami in Germany did dyno runs and reckoned stock was optimum, so reverted to stock Never Had one - German Export 45, 15 Tooth Exhaust is louder than I would like, definitely Maximum performance gain from rejetting. I had the baffle out to try it but it was way too loud. Finally got low end power I wanted when I changed to #45 Pilot after running stock Pilot for 5000km. Sudco Manual reckons each circuit is additive. I also replaced the carb venturis and put in new needles (one was scored, possibly due to leaky coolant going into the snorkel). This seemed to give me better mileage. Added Stiffer Clutch Springs (Team-Pami) which helped a bit, but possibly because I also replaced the clutch at the same time. 5th from Top was way too Rich and bogged down, 4th (Stock) seemed OK, but lacking 1/4-1/2 throttle power, so I'm trying middle at the moment as recommended by Staintune when I got their pipes. I was also told by Factory that they thought K&N was perhaps not so good for valves, as it lets in a bit of dust/gunk,. Their impressions were stock foam filter was just fine. Team-Pami said they did some dyno runs with timing modified and also reckoned stock was the most efficient, but it depends where you run your normal rev range.    
Kristian (Try #2) #562 F650 1996/1997, 24850 Miles. Bike has all same stock Carb Jets/Needles as US 1997 onward Model. Organ pipes drilled out but PLUGGED. Staintune Slip-on, Baffle left in Stock #135 Mikuni's Stock #41.3 Stock Needle 3rd (Middle) clip from Top Stock, but checked and modified back to stock - it was out 2.75 - 3 turns out. N/A N/A Sea Level (Hong Kong) Tried Woods ignition advance, but Team Pami in Germany did dyno runs and reckoned stock was optimum, so reverted to stock Never Had one - German Export 45, 15 Tooth Exhaust is louder than I would like, definitely Maximum performance gain from rejetting. I had the baffle out to try it but it was way too loud. Finally got low end power I wanted when I PLUGGED the Airbox Organ Pipes again and changed back to #41.3 Pilot. Dyno Springs gave me a Stutter Mid Range so took them out and went back to Stock Needles 3rd Clip, with the Snorkelectomy for the VR th eonly Airbox Mod. Not Superpower, but good comprome power/gas Mileage    
Michael #563 F650 1997 , Just over 27,000 miles, second owner at 6000miles. Organ pipes drilled out and snorkel removed  Staintune with baffle in but enlarged restrictor outlet  Stock #138, Dynojet Stock 2nd from Top, Dynojet Stock 4 turns out. N/A N/A Sea Level (San Diego) N/.A Yes. 40-45, 16 Tooth Staintune pipe sounds great and the rejet does squeeze a little more power from the thumper.  Power wheelies are easier and the 5-6K RPM grunt is more evident. I am using a dynojet kit installed following the recommended settings. The only part of the carbs I adjusted were the mixture screws.  Maybe I should try raising the needle in hoping to find sum midrange boost.  I will be taking my carbs down for cleaning because I lost a little top end speed. I also push the single to it limit quite a bit yet this single keeps wanting to be rev to the redline.  My only dislike is poor water pump design.    
Mike #639 F650 GS 2001, 07/00 Build (2) 1 inch holes drilled in snorkel Staintune Slip-on, Baffle left in Stock Paper N/A N/A N/A N/A N/A R1200C injector Stock - no upgrades 500 ft (ride from SL to 6K ft) N/.A No 55 Exhaust is louder than stock.  With baffle removed a lot louder.  Surging is gone.  Stalling remains - perhaps a little less.  Noticeable increase in power in low to mid range - on top too, but not as much.      
Andrew #700 F650 GS 2001 GS, 07/00 Build No modifications Staintune Stock Paper N/A N/A N/A N/A N/A R1200C injector Stock - no upgrades 670ft Chicago None No 50 My Dakar has 1000 miles and before modification would stall occasionally and surge around 3600 RPM.  First I put a staintune on and the sound and look are very nice.  I left the "dead" right side can for symmetry.  Next I made a 1200c fuel injector swap.  After both modificaitons the bike does not surge and has only stalled once.  Low end power is better with power wheelies possible in 1st and 2nd gear.  I rode the bike for an afternoon with the snorkel removed and noticed no change so it was reinstalled.  Total cost of staintue+FI = $615 and 1.5 hours labor.    
Larry  #705 F650 ST 1997, 12000 Miles Stock Remus Stock Stock Stock Stock Stock Stock N/A N/A Sea Level - Tampa Bay Stock Yes. 52-58, 15 Tooth No surging or stalling or flat spots anywhere in the rpm range, sound level pleasing to me - quiet compared to my Harleys, Lucky and surprised it ran so well without mods that I expected to do. 15 tooth front sprocket and I still get that mileage.  (may change back to 16 as Florida is not challenged for hills and starting out) I did NOT notice any change in performance with the Remus.  Expected it to be less and have it camoflouged by the sound. Felt for that very issue and detected nothing.  Top speed was an indicated 97mph with stock muffler and Remus. (Florida back roads are great for speed bursts) Did plug chops before and after the Remus (AR) and saw no change.  No "flat spots" AR.  If any change presented itself I think the bike warms up to a perfect idle almost instantly AR but I seem to remember it took a couple of minutes with the stock exhaust.  That was not something I prepared to check. Weight was less than stock but I have no printed figures.   Bought it from Mr.Eds so contact them through the F650 site for specifications.  Nice people there. Remus is solidly made with easy, solid mounting.  Mine is the cheaper aluminum version and it has held up to a winter of coastal salt air with no hint of corrusion or dulling.  Looks "good" on the bike and gets compliments for both looks and sound. Distinctive sound is fine at idle and going out in the mornings.  High RPM produces some pleasing volume, as does 'blipping' the throttle like the Harley guys like to do.  Wind noise covers up the exhaust sound at freeway speeds or higher so, for the rider, it's not an issue.  
Randy #748 F650 1999  13,000 Miles Stock Staintune Slip-on, Baffle left in, but with 6 holes drilled in baffle Stock Stock Stock Stock Stock Stock N/A N/A   Stock Yes. Mid 40's, 16 Tooth Fuel mpg did not change at mid 40's. I did drill the stock Staintune "baffle" with six new holes to releave a small amount of back pressure that the baffle produced. It made the bike a little louder, also. These wholes can be reversed easily if desired. I know some of the things you mentioned can produce more HP, to nearly 60, I've heard, but I've never had a need for it and it may/may not have other effects like shorter engine life.     
Chris #782 F650 1997  15,000 Miles Organ pipes drilled out but not removed, Snorkel Removed Stock K&N filter. Stock Stock One needle raised one notch, second needle stock Stock 3.5 turns out N/A N/A Sea Level Stock Yes. 44, ?? Tooth, Varied city/freeway/Country Rd Performance: Much better low speed/low rev performance. Engine is also smoother. More positive roll-on throttle response. Slightly more power across the rev range. Louder intake noise, exhaust the same. Thoughts: I believe the bike to be very sensitive to airflow/fuel mixture and altitude. I think I have the bike in the best configuration for the lowest amount of money possible. Still would like to compare to other bikes.
jpd #793 F650 GS 2001, Just Broken in Stock Staintune Stock Paper N/A N/A N/A N/A N/A Stock Being Upgraded N/A Stock Not Given Not Given My pipe is on a 2001 F650GS. It's the only modification so far; no filter, sprocket, etc. changes. Bike wasn't completely broken-in when I put on the pipe so I can't attest to how much of an increase it provided. Seems to have added a little grunt in low & midrange. The bike is in the shop right now, because of a blown starter or something, and they will do the re-mapping at the same time. At first the bike seemed to surge less with the pipe, but right before it went into the shop the surging got really bad(between 3-4000rpm). Pipe is noticeably louder than stock, particularly when on the throttle, but it sounds really good. Fit & finish are excellent and installation was a breeze. Most pipes won't improve top speed much anyway, instead improving midrange where you spend most of your time. As you say, the engines & exhausts are so well engineered these days that there's not much to be gained from an aftermarket pipe. However some configurations(big singles & twins) are so muffled to pass noise & emission standards that they respond well to better flowing pipes. My Buell easily gained 10 or 15 hp from a pipe & airbox.    
Anonymous #1 # F650 1999, ? Miles Snorkel NOT removed Remus Stock #138, Dynojet.  Stock Stock needles w/ clip at 4th notch from top, Dynojet springs Unknown Somewhere around 3-1/2 turns. N/A N/A Unknown Stock Unknown Unknown Power is smooth and plentiful from just below 3K to red-line. As you indicated to me in the past, it can be a PITA to get it right. In my case it took several K miles and a half dozen attempts. Would probably have been shorter if I had access to a dyno and hadn't listened to the folks at DynoCrap. Anyway, I wanted to forward the info to you in case anyone else you sell a REMUS pipe asks what has worked. Snorkel was put back onto the airbox and I'm still running the stock air filter element. My biggest problem was the Dynojet needle didn't work because the tip profile was too aggressive making the midrange run too rich and the stiffer stock springs hurt the low end response giving a bit of hesitation when transitioning from power-off to power-on. Hope this info can be of help."     
Anonymous #2 # F650 ??? Removed organ pipes from airbox but retained snorkel but can try removing that too. Arrow K&N filter. #140 Unknown Dynojet needle, 2nd from top. Unknown Unknown N/A N/A Unknown Stock Unknown Unknown Maybe I can be of some help...I have Arrow and K&N filter fitted and complimented this with a Dynojet kit (some claim Factory is better but seems to be little in it really). The Dynojet comes with main jets 138 and 134 (138 for aftermarket exhaust 134 for standard) and new profile needle, clips and washers. I initially fitted the 138's etc and then went to 140 jets (standard on early Euro spec bikes!)Needle clip two from top. Bike now literally FLIES... Good luck. PS removed organ pipes from airbox but retained snorkel but can try removing that too...    
Andrew its in the mail - really! F650 1997, 11800 kms Stock Staintune Stock Stock Stock Stock Stock Stock N/A N/A Sea Level Stock No - no backfiring except very very rarely - cannot reproduce it so really not a problem - but didn't do it all with the stock exhaust 20-25km per litre Stock Staintune with removable restrictor left in place added to almost stock f650.  The only mod is 15 tooth counter shaft sprocket - this makes the bike much smoother to ride (no snatching at low speed), I would only go back to the 16 tooth if I was doing lots of highway miles at speeds above 120kmh.  It sits on 4000rpm at 100kmh which is comfortable, and will still do 160kmh around the race track and was still pulling  (didn't want to red line it!).  The Staintune looks like a work of art and is lighter than the stock exhaust.  It bolts straight on, with some fiddling required to line up the header extension pipe bolt on the frame riser (a couple of mm out on this one - but it went on after some 'manipulation').  With the Staintune the bike seems more willing to rev, and is smooth throughout the rev range with no jetting changes. Power output not discernably different in my opinion.  It sounds so much better - a low note now rather than the annoying 'pop pop pop' sound of the stocker - there's less 'crackle' in the exhaust at speed which makes it seem smoother.  This translates to a much more enjoyable riding experience. Absolutely recommended.    
Tom slacker F650 1997, 29,200 miles Snorkel removed Remus  Stock, lightly oiled #137.5 Factory Pro #45 Stock Needles, clip at #3 (middle) Levels around 13.5mm 3 turns out. N/A N/A Portland, OR avg 173' above sea level N/.A Yes, oooops. ~44mi per US gal w/ stock 16 tooth Fine tuning the carbs is a labour of love…  First had problems about 1.5 yrs ago with low end richness.  Bike would bog out at idle, after being warmed up.  Did some reading (without the great spreadsheet) and stumbled upon the Factory Pro site and their section on emulsion tubes (aka needle jets) for Mikuni CV carbs.  Thinking a worn tube might be the issue, replaced them and installed the jet kit.  (Talk about a crash course in carbs...)  Well, this didn't solve the issue but did thoroughly piss me off.  Turns out the float valve wasn't shutting off, allowing fuel to keep flowing in even when there was no lack of fuel in the bowl.  Fuel was dumping out of the airbox, and from the factory, the lowest drain hole in the airbox is plugged, not allowing the excess to escape.  (Aside, I religiously shut off the petcock everytime the bike is turned off, now).     Yes, the tubes were worn, and replaced those.  The float valve was the real issue here, and solved the bogging out/fuel dump.   But, IMO, the Factory Kit doesn't work w/o airbox mods.  If all you do is change the needles, yeah, it will pull like a mofo at full throttle, but that's just because of the agressive needle taper.  You lose rideability, cruise is tooooo  rich.  Tried to compensate w/ needle position and float height, but to no avail.  Finally went back to all stock January 2001 and got back to 46mpg fuel economy.  After contemplating rigging a Supertrapp ( to save on $$$$) on the exhaust end, a Remus fell into my lap for about 1/4 of retail.  Hot DAMN, sounds like a Ducati SuperMono.  (Just yesterday I was at the dealer and a mechanic was equally impressed w/ the sound, felt compelled to come over and talk about it....).  Fit and finish are very nice, also.  So, now the bike really could use the rejet.  Mains:  stock (132.5) will work, but modify your intake and go at least to 134(135).  I'm running 137.5 (Factory Pro) right now and rips.  I think 140 will work but probably would require organ pipes drilled out.  Pilot:  without airbox mods, running stock (41.3) pilots is fine, but go w/ 45's is intake is modified.  Turning the 41.3's out enough w/ intake mods gets close (conjecture) to the end of the usable range of the mixture needle.  42.5's are also available (Factory Pro), and may be an option for stock configs or mild modifications.  Needles:  those damn Factory needles...  Whatever config I've tried, the Factory Pro needles seem too agressive to retain driveability at cruise.   I think that even a small movement up or down changes the mixture so much that it is not smooth.  Right now using stock needles @#3 position from top.  Pulls smoothly and cruises well.  Think about using the Factory needles for the track, but I can't recommend them for street.  Float height:  my verdict is still out on this as to how much this affects delivery.  Wish you could adjust w/ a screwdriver w/o removing carbs.  Very difficult to get an exact setting, as holding down the float cage is difficult to keep still/hold down the same as other carb.  If you want to rejet w/ a new pipe, buy a couple pilots and mains from a dealer and bypass Factory or Dynojet.  These are common carb parts and the stock needles work well.  If this isn't enough to satisfy, buy a different bike or buy some dyno time, or gooooood luck.  I can't say enough about the Remus sound...  Remember that temp and humidity play a big role (bigger than I thought) in the tuning process.  Make sure your engine is up to full op temperature.  I've tried to tune it for summer heat, as in the winter you can add richness to the entire range by turning out the mixture screws a tad, to compensate for the denser air (which results in a leaner mixture).  tjs 2001.08.02
Dave #365 F650 classic 1999 , 6500 miles Snorkel cut back for VR relocation, organ pipes open up Remus- GrandPrix K&N filter. Mikuni #137.5 41.3 stock Stock Needles #3 clip Stock springs 14.mm 3.5-3.75 turns out N/A N/A 100' ASL N/A Ya first day I owned the bike??? Go figure? 42mpg US gal I had a dealer do a Dynojet kit but he never check the float levels, bike ran poor for 1.5 years due to levels left at 9mm. Poor fuel mileage (30mpg). I took out dynojunk and decided to start over. This is were I ended up, I also replaced venturi jets and needles, slide springs along with O-rings. Had one bad plug cap, tried NGK 5k caps tested 14.6k & 13.8 total resistance, replaced with New Beru's now both at 9k total (cap,lead, coil). 5/21/2002    
Chas #1969 F650 classic 27k Miles Airbox with an air-enricher ectomy and snorkel-ectomy and organ pipes Stock Muffler Decatted Stock DJ 134 Main N/A DJ Needle 2nd Clip 14.6mm 3.5 turns out N/A N/A N/A N/A     So the last 3-4 weeks I redid the carb with dyno-jet and replaced all the insides, then the airbox with a air-enricher ectomy and snorkel-ectomy and organ pipes .....  then air fillter is the same so......  the exhaust is stock but the Cat was taken out by my friend with a arch welder.  Then the weakest thing .....  was replaced ....  the stock shock now it is a Olmhs.  but also all the bearings in the swing arm and arms ....  all replaced with caged bearings ...  torringtons and repacked :))) The cooling pump was old and weeped so a new cooling pump with seals .  then all put all back together ........  Many Hours and today all done! I took it out today and the carb and exhaut mods make the bike FLY!!!!!!!!!!!  WOW!!!!!!!  So many things I missed in the details but the FAQ's and the people that help each other in the Chain Gang make the F 650 the BEST !!!!!!!!!!!!!!!!!!!!!!!!!!!!    
Respondents 18
Big Thanks to all the Contributors & Special Thanks to Flash. Humble apologies for pestering the board, as always there's more questions than answers.
Just so no one gets really upset, the performance results are all opinions. Any Modifications MAY void your warrantees, so check first.
If you can contribute to this register or know of know of anyone who can, please email the Webmaster at www.f650.com
Once you've done your modifications, please give something back: Send in the details of your mods, with your impressions or better still dyno runs.
Thanks & Rgds. Kristian #562
kg Pounds
Average$/km       Weight of Stock Muffler = The OEM unit and clamp weigh 5.3 kg 13.5 Thanks Tedd A
1 Gallon =  3.7854118 litres Weight of Staintune (F650) =   <---Anyone Know These.?
1 Mile =  1.609347   km Weight of Staintune (F650GS) =  
Weight of Remus =  
Weight of Laser =  
Weight of D&D =  
Weight of Arrow =