Dyno chart of a 950 Adv -- jetting suggestions?

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Orangecicle, Oct 1, 2010.

  1. Orangecicle

    Orangecicle On a "Quest"

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    Inmates, I've been all over on jetting of my '05 950 Adv. I think I'm finally close, but my seat of pants read of the bike told me I was lean on idle because I was getting runup of RPM on idle. The dyno chart shows this was right:

    [​IMG]

    See the lean mix bump when on pilot? :umph Gotta fix that. Here are my current settings:

    Mains: 160/165
    Pilots: 45s
    Floats: 3 mm
    Needles: Factory Pro stuff on the middle clip
    Mix screws: out 1.25 turns
    Altitude: 850 ft, roughly

    The dyno guy suggested that I go to 47.5 pilot jets and go to 1.5 turns out on the mix screws. His thinking is that the bigger pilots will take care of the lean at the beginning of the chart, and the additional mix will keep the remainder close to appropriate but favoring slightly rich (particularly in colder months on the way).

    Any thoughts? Frankly, I've never seen an ADV with pilots larger than 45s, so I'm curious what everyone else thinks.

    And let me add: Every bike is different, so my jetting ain't gonna be like your jetting. If you put my jetting in your bike, 99.9% of the time it ain't gonna work! :deal I'm just trying to get advice on my jetting issues.

    Much appreciated!
    #1
  2. redbastard

    redbastard Long timer

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    I've got the stock pilots , and a 170 and 172.5 main jets. Needs to be one size smaller. I'll go wth a 170 rear , 167.5 front

    [​IMG]
    #2
  3. Orangecicle

    Orangecicle On a "Quest"

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    Here I go again trying to get my 950 jetted right. Based on the dyno information above, it looked like my bike really wants larger pilot jets. Well, they don't make larger pilot jets than 45s. So . . . I started fresh. Called the guys at Factory Pro, and they gave a couple of thoughts. My first effort at a rejet was as follows:

    Mains: 168/172
    Pilots: 45s
    Floats: 2.5 mm
    Needles: Factory Pro on the middle clip.
    Mix screws out: 2.25 turns
    Stock air filter, and no pre-filter

    The results were pretty good, but I could not get the bike to idle once heated up. Basically, she felt lean (significantly) again, with either a runup on RPM from 1,400 to about 1,800 while at a light, or I she would stop at 1,800 for about a minute before settling down to 1,400.

    Talked to Factory Pro again, and they suggested opening up the mix by 1/2 a turn. I'm so tired of pulling the carbs out, I decided to just go to 3 turns out on the screws. Well, I rode her around tonight in about 55 degree temps, and I was still having a little trouble getting the bike to idle down at a light. Otherwise, I would say that the bike feels slightly fat.

    I could start trimming on the mains and go back to the stock position on the needle. But, it's disappointing to me that I just can't get the bike to idle perfectly. And, it seems that if I start coming down on the mains or the needle that it just makes the idle situation worse.

    Very frustrated at this point. Any thoughts appreciated.
    #3
  4. A.Vern

    A.Vern One Man Wolf Pack

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    I'm very interested to see how this turns out.

    My '04 is doind the same thing.... Starts up at 1400, then runs itself up to 1800. Is pretty annoying at lights and causes the bike to run hotter than normal.

    I thought it was a vacuum leak, but repaces all the intake manifold hoses with no improvement.

    My next thought was faulty throttle position switch...

    I've got FMF pipes on my ADV with unknown jetting from a pevious owner.
    Would running lean really cause the idlle to wander so much?
    #4
  5. Flanny

    Flanny Flanny-it-up!

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    Have you completely ruled out any air leaks?
    #5
  6. Orangecicle

    Orangecicle On a "Quest"

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    You bet. The vacuum lines are all removed and manifold ports plugged with bolts coated with Permatex. The rubber boots under the carbs look good, and the carbs are properly seated. The bike has 25K on her, so I don't think it is carb wear. TPS is properly set at .5 volts when off throttle. Carbs are properly vented out the bottom of the airbox. The bike has non-cat Gualdi exhaust, and I've removed the SAS and Canister. Tanks vents are run per the H.O.W. behind the radiator to open air. The only mod I've not done to her is the flapendectomy, which I don't think would be an issue here.

    I would note that the bike seems to run fine in the morning when cold. She just needs a little choke. However, by the time that I've ridden 15 minutes to work on the interstate, she has the problem of runup on idle. Do you think that it could be the stock fuel pump dropping pressure once the bike is heated up and getting into a lean condition because of lack of fuel???? I'm just running out of ideas. My next venture might be to remove the mix screw all together. :lol3

    A. Vern, it sounds like we have the exact same issues, and I'm about fresh out of ideas. But like Flanny, I can now disassemble and reassemble a 950 Adventure blindfolded!
    #6
  7. Flanny

    Flanny Flanny-it-up!

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    It's possible the bike is actually jetted so rich on the pilot circuit, that in order to compensate, you've had to turn your idle way up, thus leaning out the mixture with the butterfly valve opening.
    #7
  8. A.Vern

    A.Vern One Man Wolf Pack

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    Another symptom mine has is when I ride at elevations higher than 8000 MSL I need to bring up the RPM or she almost stalls out. I've heard from other 950 riders that this isn't normal.

    I was just up at Dusy Ershim 3 days ago and adjusted the RPM to keep it running. When I came back to sea level, the RPM that I had adjusted to keep it at 1400 RPM was up at 2200.

    I reset 1400... and had the same issue with run up.

    Could this be too rich?

    I'm planning to put all stock needles in so I have a base line to work from.

    A mile in from the North side of Dusy Ershim looking over the Sierra (alt 10K MSL).

    [​IMG]
    #8
  9. men8ifr

    men8ifr Been here awhile

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    From a basic point of view if you're OK when cold but the problem gets worse once fully warm that would indicate too rich unless there is an air leak which opens up once the motors fully upto temp.

    Don't forget idling with the throttle shut is very different to being at the same RPM but throttle wide open as per your dyno run...

    Also the mixture screw should mostly control fuel at idle but if you have to move that to the limit of its adjustment then it's time for a different pilot jet.

    Is it possible to idle the bike with tanks removed or whatever so you can get to the mixture screw, If so i'd set the bike idling filly warm then adjust the screws one way then the other to see what improves the idle. Again I'd look for fuel mixture giving max RPM then adjust your idle speed control to give the rpm you want.
    #9
  10. Orangecicle

    Orangecicle On a "Quest"

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    Yep. Going from 2.25 turns out on mix to 3 turns out makes the idle problem worse -- by far. She smells like the Exxon Valdez, too. Next try is dropping 1/2 turn in from where I was -- down to 1.75 turns out. If that won't calm down the idle, I dunno. Maybe Flex Jet 2s!!! Maybe trying the 42 idle jets again.

    I'm apparently more hamfisted than you, and I don't think I can get my hand in that little triangle door with a screwdriver. :rofl
    #10
  11. dad2bike

    dad2bike Retired! Cranky Old Fart

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    I fully recommend doing the flex-jet remote screws. I've got one of the original sets that Dean developed. http://www.r1dean.com/cart/index.php?main_page=product_info&cPath=26&products_id=52

    I can tweak my mixture whether in the mountains or change of outside temps. All done sitting at a long stop light. :clap

    I'm watching your thread to see ideas for improvements for mine.
    I recently put a BMC filter on with my Prefilter. Seems like I gave up quite a bit on the top. Since I do mostly street, gonna give the BMC with just the snorkle a shot. Also go back to the larger mains when I do.
    I'm running the H2W jetting in mine.
    #11
  12. Orangecicle

    Orangecicle On a "Quest"

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    A. Vern, you're describing a rich problem. Did the bike run well when you bought it? Was the bike set for a different elevation?
    #12
  13. A.Vern

    A.Vern One Man Wolf Pack

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    The bike ran well when I bought it, but I did have to adjust the idle as I rode home from Albuquerque, New Mexico (fly and buy) to sea level in Central California.

    I didn't notice the surging idle issue until I took it to KTM Reno and had them do a valve adjustment, water pump job and the head nut TSB.

    When I got it back, the idle was real bad, setting 1400 first, then it would hang at 2000, then randomly drop to 900 and almost stall and then back to 1400.

    I replaced the air filter (dirty), took the carbs off, redid the intake manifold bolts on the left and new hoses on the right and redid the Y hose and dropped two hoses through as the Canisterectomy calls for.

    This helped the surging go from 900-2000 to 1400-1800.

    Better, but still not right and I have to increase the RPM at high altitudes.

    I guess the only thing to do now is put in stock needles and see what that does?
    #13
  14. Chuckracer

    Chuckracer Jerkus Maximus

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    I'd switch back to the 42 pilots before I dropped the needles.
    #14
  15. Flanny

    Flanny Flanny-it-up!

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    Yup - go back to stock and start over. I would also ditch the factory pro, which from all accounts sets the bike up way too rich.

    If you want to keep the 45 pilots, then you need:

    45 pilots, # 70 secondary air jets, stock needle 3rd clip, and IMS at 1.25-1.75 should be in the zone.
    #15
  16. Orangecicle

    Orangecicle On a "Quest"

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    Well, I don't have #70 secondary airs or stock needles. Hmmmm.

    I tried the 45s set at 1.5 turns out, and that was way too rich -- exact same idle problem.

    I've pulled out the 45s and switched back to 42s with IMS out 2 turns. Still rich and still with the hot idle problem, so going in on the screws to see what happens.
    #16
  17. Orangecicle

    Orangecicle On a "Quest"

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    Latest test:

    168/172 mains
    42 pilots
    FP needles on the middle clip
    floats at 2.5 mm
    IMS out 1.25 turns
    Stock filter

    This seems close. The bike settles down to a standard idle when hot, but then it hunts up on RPM a little as it sits there. I also see a touch of white smoke on hard bleeps of the throttle. So, all of that sounds a little lean, which sounds about right with 42 pilots, slightly rich floats, and IMS a little tight. Identical settings with the IMS out 2 turns gave me the hangup of throttle when going back to idle, which I think sounds rich on these carbs. (These Keihins are dang tricky!).

    I'm going to try the above settings with the IMS out an additional quarter turn at a time 'til I find something that works. I think I'm closer than I've been in a long time.

    Does anyone think the larger-than-average mains have an impact on idle? I think the answer is no, but I'm just a newbie.

    UPDATE: Screws out 1.5 is better, but she still hunts for a consistent idle between 1,400 and 1,600. I think I'm going to 1.75 turns out and calling it a weekend.
    #17
  18. dad2bike

    dad2bike Retired! Cranky Old Fart

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    Float level would have more of an impart on the bottom.
    #18
  19. Orangecicle

    Orangecicle On a "Quest"

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    OK, I found a setting that works.

    Latest test:

    168/172 mains
    42 pilots
    FP needles on the middle clip
    floats at 2.5 mm
    IMS out 1.75 turns
    Stock filter

    What is odd is that I've not seen anyone with settings like this before. And, I'm finding that my bike with these settings is VERY sensitive. I tried these settings at 2 turns out on IMS, and that caused hangup when coming off of throttle -- suggesting rich. I dropped down to 1.5 turns out, at which the bike would not hangup when coming off of throttle, but the bike would then "hunt" for an idle between 1,400 and 1,700. I then went to 1.75 turns out, and the bike seems to drop to idle and hold the idle. So, my bike would appear to go from rich to lean in 1/2 of a turn of the IMS, at least with my settings. Go figure. :confused

    And, I'm back to the 42 idle jets. Pyndon told me to take the 45 pilots out of it, and he was right. :thumb There is no way with my settings that I could have dialed down the IMS enough to make it work. Thanks, Pyn. It just takes me a while to get it.

    I would also note that this is not even close to what was suggested by the dyno. Who knows. All I know is that now I have a bike that will idle, and it seems to run well otherwise. I pushed it to 105 mph indicated on I-35 a bit ago just to see what it would. :eek1 The footpegs vibrate like hell at that speed, but otherwise, fine.

    And, I want Flex Jet 2s for Christmas.
    #19
  20. dad2bike

    dad2bike Retired! Cranky Old Fart

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    They will really help you with this stuff.
    I typically run 1.75 at home (1500') and when at Lake Tahoe (7600') I turn it in just .25 change. Don't take much.
    #20