Any Honda Dominator NX650 owners out there ?

Discussion in 'Thumpers' started by KeithDommirider, Jul 31, 2007.

  1. Thunder Dan

    Thunder Dan Been here awhile

    Joined:
    Sep 19, 2008
    Oddometer:
    797
    Location:
    Hunter Valley, NSW, Australia
    G'day Guys,

    Just came across this while looking at the Boano site.
    Apologies if this was already known.


    Cheers,

    Dan. :D
  2. adkfreeridex

    adkfreeridex Adventurer

    Joined:
    Mar 29, 2011
    Oddometer:
    39
    Hey guys I finally got around into diving into my bike to figure out the low mileage issues and poor performance at higher altitude. First, someone regeared it to 13/45. I brought it back to stock (15/45). I pulled the carb and cleaned it, although it was not very dirty. It still has stock jetting (48/155). However I still get 33-35 mpg, and performance going from 5500-8500 is worse (obviously from regear, but still not good when when im climbing. when I get on the gas at lower altitudes it sometimes hesitates with a jerk at greater than 80% throttle in higher gears. It also wont maintain power at rpms lower than 5000 starting at ~6500'. Ive been reading that the bikes are jetted lean, so Im not sure if jetting is my problem here. Also the bike has dual marving exhausts, not stock, so Im not sure if this is affecting the performance. I dont care much about power, but would like better fuel efficiency and a smoother ride at altitude. It is an '88 with 18000k. what should I try next?
  3. slowhatch

    slowhatch Adventurer

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    Jun 12, 2010
    Oddometer:
    22

    Finally got information about the tanks. They list in in their catalog but the tanks are still discontinued with no plans to make any. Back to watching for a used one.
  4. FLICKIT

    FLICKIT Been here awhile

    Joined:
    Aug 9, 2011
    Oddometer:
    881
    Location:
    Down-under Down-under
  5. Bounder

    Bounder ExternallyDisplaced

    Joined:
    Mar 2, 2011
    Oddometer:
    991
    Location:
    West Cork, Ireland
    Have you tried the Carb mods suggested here
    Mine stumbled a bit before but after doing the mods it runs a lot smoother. Altitude jetting I can't help with not many places over 300m here!
    Try looking for jetting specs for the XR650L for high altitude.

  6. Pasoren

    Pasoren Adventurer

    Joined:
    Oct 1, 2012
    Oddometer:
    13
    Any experience with Dave's mods on stock exhaust/air filter? I have read it may not have any effect on stock systems.
  7. Bounder

    Bounder ExternallyDisplaced

    Joined:
    Mar 2, 2011
    Oddometer:
    991
    Location:
    West Cork, Ireland
    No idea, Mine came with a Supertrapp and I fitted a BMC filter.
    I also had a California model Carb on mine which I changed for a German market carb and I have removed the top of the airbox snorkel.
    I see at the bottom of that page they say that the mods might make it run worse with stock airfilter and exhaust.
  8. mas335

    mas335 xendurist

    Joined:
    Jun 17, 2006
    Oddometer:
    1,987
    Location:
    Piedmont region NC
    I may be selling a Acerbis NX tank soon, pm me if interested in details.
  9. adkfreeridex

    adkfreeridex Adventurer

    Joined:
    Mar 29, 2011
    Oddometer:
    39
    I have not modified my carb yet. Reason being, if bike is stock jetted lean(at sea level), and after market mufflers are on (which should lean it out further), and I'm at 5000' I still might be a hair lean, but problems should dissipate by climbing through to 8500'. Creating a richer mixture which is what the mod will do, would only make thinks worse up high. I think. My bike feels like it has plenty power at 5000'. But the 35mpg(at best) seems 10-15 low. This is the only motorcycle if ridden besides a gs1200r, so I don't have anything to go by in terms of power. It won't wheelie, not sure a properly tuned one can, but if that's an indicator I hope it helps. I'm inclined to try Dave's mods, but don't want to permanently alter anything if I don't have to. Thanks!


    Forgot to add that someone before me Desmogged it but left oil separator on
  10. adkfreeridex

    adkfreeridex Adventurer

    Joined:
    Mar 29, 2011
    Oddometer:
    39
    [​IMG]

    [​IMG]

    here are two pics of the plug (one with flash and one without), i tried to compare them with photos of plugs on the internet and my conclusion is that im running lean, can anyone confirm this? however, If i am running lean, why does my problem get worse with altitude?
  11. Bounder

    Bounder ExternallyDisplaced

    Joined:
    Mar 2, 2011
    Oddometer:
    991
    Location:
    West Cork, Ireland
    I can't answer any altitude questions.
    But looking at the available specs from the XR650L engine it would seem that the usual jetting for over 5000ft is 55 pilot and 155 main,
    All bikes are different, but I would strongly recommend Daves Mods its not just richer its also the way the mixture is delivered at different throttle openings.
    Raising the needle is easy enough and reversable if necessary,
    What condition is your air filter in? Its easy for them to get all clogged up with the oil mist in the airbox.
  12. jeepinjeffery

    jeepinjeffery n00b

    Joined:
    Aug 20, 2009
    Oddometer:
    9
    Location:
    Utah
    Just found this site, again. I'm going to read all the previous posts but I am about to pull my Dominator out of storage and prep for riding this season. :clap
  13. adkfreeridex

    adkfreeridex Adventurer

    Joined:
    Mar 29, 2011
    Oddometer:
    39
    So in an effort to try and find the cause of my poor mileage and loss of power, I adjusted my valve clearances. All were pretty close to spec, but the right exhaust took about five full turns out before I could get the gauge in. I buttoned everything back up, and the bike runs good, seems smoother but it could be because I want it to. But now I'm getting loud tapping from what I think is right exhaust valve. I have searched and found that it is connected to a decompression unit and that my method for clearance wont work. can anyone tell me how to properly set the clearance on this valve? Thanks!
  14. FLICKIT

    FLICKIT Been here awhile

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    Aug 9, 2011
    Oddometer:
    881
    Location:
    Down-under Down-under
    You need to turn the engine just past TDC (top-dead-center) so the decompresser releases that valve before you check it ;)

    EDIT:
    From memory you usally hear a "clack" as the decompresser lets go, you only need to go about 5 degrees past TDC...

    With the valve loose as it is now, you should be able to turn the engine past TDC and see when the gap opens up to know when the decompresser has let go...

    Good luck :)
  15. FLICKIT

    FLICKIT Been here awhile

    Joined:
    Aug 9, 2011
    Oddometer:
    881
    Location:
    Down-under Down-under
    How bad is your mileage? (just out of interest)

    My bike ran great... but mileage varied a heap depending on how hard I was pushing it...

    Best was around 20Km/L (47mpg) when cruising slow n easy ...
    Worse was around 13Km/L (31mpg) when hammering it around offroad...
    (average was 16-17Km/L (39mpg) when cruising around the forests without hammering it too hard)
  16. adkfreeridex

    adkfreeridex Adventurer

    Joined:
    Mar 29, 2011
    Oddometer:
    39
    I get 32-34 mpg no matter how I ride the bike around town. I will be satisfied if I can get 40.

    Flick, thanks for the tips on that valve. Bike is back together and it sounds and runs good. It seems be accelerate quicker and throttle response is snappier, it also seems to chug less at low rpms. I hope this helps my fuel economy. The guy at the parts place looked at my plug, and with mods bike has recommended a 165 main. Ill run ~50 miles with valve adjustment and re calculate mileage to see if it will help. If not ill try that bigger main.
  17. Dr LC8

    Dr LC8 ...soon or later

    Joined:
    Jul 4, 2005
    Oddometer:
    970
    Location:
    Manchester...but from Rome!
    Any chance to find one still around for sale?

    Nic
  18. Skapegoat

    Skapegoat Adventurer

    Joined:
    Sep 10, 2012
    Oddometer:
    96
    Location:
    Ireland
    I assume your air pump on your carb is working correctly?
    Where the throttle cables attach to the carb is like a cam, there should be an arm with a rubber tip tracking along this.
    Sometimes these arms stick open with dirt/corrosion etc.
    Mine ran like a sick puppy until I realized this was the problem.

    Now it's much better!
  19. Carlossal

    Carlossal Professional dreamer

    Joined:
    Feb 25, 2010
    Oddometer:
    15
    Location:
    Mid North Coast, NSW, Aus
    Hi all,

    Posted on here a coupla years ago but have been lurking ever since. Still have an '89 Dominator with about a million k's on it but have a couple of tech questions:
    1) I'm reading the workshop manual trying to pull my forks to pieces to check bushes as I'm replacing fork seals and oil. I've removed the fork slider socket bolt (on the bottom of the forks - allen bolt with copper washer) and now the fork piston and return spring have slid out the top. The manual says to move the fork slider in and out, "tapping the bushing lightly" until fork tube and fork slider separate. Does this mean, just keep working it in and out until they separate - the slider pulling out the bushing? I can't see any other way I can tap it.

    2) I have the brake off too, and am trying to replace the pads. I say trying because I successfully took the old pads out, but now the new ones won't fit in :huh. I suspect my piston is very very sticky, and wondering how people get around this. Put the old pad back in and hit it with a drift? Soak the whole lot in WD-40? I did stick a screwdriver in there when I was taking the old pads out; but didn't notice that the pistons didn't move. I notice now :D

    Any help much appreciated. I was getting spongy braking, really soft suspension and repeated diving and rising on braking, so figured suspension and brakes both needed work. I'm replacing disk as well as pads, but wasn't planning to do any more on the suspension than fork oil and seals.
  20. MartinPetren

    MartinPetren Swedish Adventurer

    Joined:
    Sep 2, 2009
    Oddometer:
    372
    Location:
    Gothenburg or Uppsala
    Hi everyone, I have a NX650 from '91 that has a blown rear shock. I am currently searching thru Ebay for a used one. Is there by any chance any other shock from another model or brand that also fits?

    I hope to get some advice as I'm sure the bike is still bouncing up and down in the garage from today's ride.

    Thanks in advance!