Theory On Our "Stalling/Stumbling" Issue

Discussion in 'TR650' started by MotocycleWriter, Jul 30, 2015.

  1. Roger 04 RT Husqvarna
    AA Class

    Husqvarna Motorcycle:
    TR650 (friend's)
    Other Motorcycles:
    2004 BMW R1150RT
    Mark, try a test and reduce the fuel in your PCV 0, 2 and 5 degree columns to 0 added fuel from 1000 to 4000 RPM. See if that improves it.
  2. hasenpfeffer Husqvarna
    Pro Class

    Location:
    CO
    Husqvarna Motorcycle:
    TR650 Strada
    Roger, that's not Mark's bike, just someone he's helping. I don't think he has a PCV.
  3. Mark_H Husqvarna
    AA Class

    Location:
    Lapu Lapu Cebu Philippines
    Husqvarna Motorcycle:
    2013 TR 650 Strada; 2015 Nuda 900R
    Other Motorcycles:
    Honda XRM 125, Kawasaki Curve 115
    Like he said !

    As a standard bike it has run like this from day one. We have no Dealer, no MOSS, no GPR 911, no nothing.
    Even fitted with Brisk Plugs it still does this.
    The bike rides great except for the stumbling around 2000 rpm and if you avoid the rev range by either slipping the clutch or powering straight through it the engine is smooth all the way. It ticks over reasonably well too.

    I have read the many posts on the theory of this stumble, throttle body fuel wetting etc etc but somehow I am not convinced they are wholly correct.
    This bike is an example of a perfect stumbler and riding it around I can actually get it to fluff and stall any time I want to just by holding it at 2000-2200 rpm, just like I did in the video. I believe other bikes that stumble have the same issue but maybe not quite as bad as this one.

    So can anyone explain why it does this ? It should have the same fuel map as any other 2014 Strada.

    The bike is now fitted with a Dyna-Boost and goes like a scalded cat, the stumble is less apparent now, but it is still there on occasions when the bike is hot in traffic.
  4. WayneC Husqvarna
    AA Class

    Location:
    Sydney
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    F650GS Dakar
    The stumble is a firmware issue and you cant predict what firmware would be fitted to a machine as delivered as it depends on the predelivery done by the dealer

    There can be other maintenance factors in low rpm problems but not the 2000 rpm aspect, fitting aftermarket ECU spoofers/PCV etc are stop gap at best
  5. Mark_H Husqvarna
    AA Class

    Location:
    Lapu Lapu Cebu Philippines
    Husqvarna Motorcycle:
    2013 TR 650 Strada; 2015 Nuda 900R
    Other Motorcycles:
    Honda XRM 125, Kawasaki Curve 115
    Surely the firmware is ex factory and not dealer. I am pretty sure the dealer who sold this bike did not have a fully functioning MOSS at that time anyway.
    This bike is a 2014 model and should have a later firmware than mine but it runs crap. I know one other bike bought same time as this one from same dealer runs totally differently, how is that ??
  6. WayneC Husqvarna
    AA Class

    Location:
    Sydney
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    F650GS Dakar
    No, normally the ECU's are supplied with either no market firmware or original default firmware, the Dealer then does the upgrade to the current revision as part of predelivery. When I looked at the predelivery schedule for the Terra/Strada available on line I noticed there was no mention of confirming the machine was properly operational using diagnostics or anything of that order and it became clear to me the dealers were unprepared for this type of machine. There will have been Dealers who understood the processes and they would have been the combined BMW/Husky Dealers or those who had been exposed to programmable systems previously
    It may be the Dealer did one machine and omitted to do the other, we can only guess but the first step is determine the firmware revision in the defective one
  7. nev.. Terrarist

    Location:
    Greensborough, Australia
    Husqvarna Motorcycle:
    '13 TR650 Terra
    Other Motorcycles:
    '14 XT1200ZE

    Anecdotal evidence (from multiple threads on this forum) would suggest that people who live close to the equator have the most problems Philippines/Darwin/Florida. Probably due to the climate/heat/humidity ?
    I think TR650 owners in cooler climates, Europe, South of Sydney AU, north of San Francisco, have fewer, if any, issues.
  8. johnsweet Husqvarna
    AA Class

    Location:
    Mount Desert, Maine 04660 USA
    Husqvarna Motorcycle:
    TR650
    Other Motorcycles:
    KTM 790R RickmanZ BulsSherpaTs350


    exactly, no issues with my machine, 2013 purchased in CT, ride in ME. Latitude 44.335788, Longitude -68.319361, mapII, an ocassional random stall in warmer weather, bone stock, soon to install oz unifilter
  9. kiwiape Husqvarna
    AA Class

    Husqvarna Motorcycle:
    650 Terra
    Other Motorcycles:
    Aprilia DD750
    New Zealand ain't near no equator.......
    engineerk9 likes this.
  10. nev.. Terrarist

    Location:
    Greensborough, Australia
    Husqvarna Motorcycle:
    '13 TR650 Terra
    Other Motorcycles:
    '14 XT1200ZE

    The tropical cyclones don't seem to know that :)
  11. mag00 Husqvarna
    Pro Class

    Location:
    Tucson
    Husqvarna Motorcycle:
    Terra, Strada
    Other Motorcycles:
    XR250 R1100RS CH50
    It's science. Your toilets swirl backwards. The Husky was made in the Northern Hemisphere and tuned to Northern Hemisphere physics. Anything not in the Northern Hemisphere is not gunna swirl the same through the intake and exhaust. Talk about a finicky system.

    Would ja look at that, I just solved the tuning issue, LOL.

  12. mag00 Husqvarna
    Pro Class

    Location:
    Tucson
    Husqvarna Motorcycle:
    Terra, Strada
    Other Motorcycles:
    XR250 R1100RS CH50
    PC5 real cheap in classifieds the other day. Microsquirt development...
  13. WayneC Husqvarna
    AA Class

    Location:
    Sydney
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    F650GS Dakar
    As with "Fuels ain't Fuels", the same applies with programmable firmware devices. Rule 1 is know which version you have
  14. Mark_H Husqvarna
    AA Class

    Location:
    Lapu Lapu Cebu Philippines
    Husqvarna Motorcycle:
    2013 TR 650 Strada; 2015 Nuda 900R
    Other Motorcycles:
    Honda XRM 125, Kawasaki Curve 115
    Yes but, like I said....with no access to MOSS, OSS or anything else, 1) How would we tell and; 2) What can we do about it anyway ?

    By the way.....we reckon we have fixed the crap running bike I posted the video of, and not with any fancy software either!
  15. MotocycleWriter Husqvarna
    AA Class

    Location:
    North Alabama
    Husqvarna Motorcycle:
    TR 650, TE 250
    Other Motorcycles:
    BMW R1150RT, BMW R100GS
    My bike is usually rock solid but was experiencing a good bit of stumbling today. Only difference was lower temperature and lower humidity. Much lower on both counts. I flipped my Wuka King dual mode switch to Low Temp and it seemed to help. Still not perfect...

    Do tell! :popcorn:
  16. Mark_H Husqvarna
    AA Class

    Location:
    Lapu Lapu Cebu Philippines
    Husqvarna Motorcycle:
    2013 TR 650 Strada; 2015 Nuda 900R
    Other Motorcycles:
    Honda XRM 125, Kawasaki Curve 115

    The fix is theoretical at the moment and I have to wait until I can get home to my bike in a week or so and get some tests done.
    Theory is based upon finding out when the nasty little purge valve is actually opening and causing the change in mixture going into the throttle body.
    Basically on that bike we disconnected the purge valve and plugged the hose, suddenly all is fixed and it runs like a dream.
    The owner was on the verge of dumping the bike, but now he is riding it like he stole it and enjoying every minute of the smooth power and no stalling which he never had before.
  17. MotocycleWriter Husqvarna
    AA Class

    Location:
    North Alabama
    Husqvarna Motorcycle:
    TR 650, TE 250
    Other Motorcycles:
    BMW R1150RT, BMW R100GS
    The symptoms in that video do not appear to be software. I'd have staked my reputation on a sensor or controller element somewhere in the control loop.

    What's the purge valve supposed to do and where is it located?
  18. big-t Husqvarna
    AA Class

    Husqvarna Motorcycle:
    tr650
    Other Motorcycles:
    ktm,yamaha
    My guess is something else is causing a rich condition and plugging the purge hose is effectively leaning the mixture.The purge valve is quite active on this bike.Here are a couple screen shots from my o-scope of the purge valve in operation.

    (of course there is always the possibility the purge valve was stuck open on the bike in question)

    This is at idle,green trace is injector and yellow is purge valve,sorry about the line hash and the cutoff tops ,I was only interested in the "on" time

    [IMG]

    and at 3k RPM

    [IMG]
    mag00 likes this.
  19. kiwiape Husqvarna
    AA Class

    Husqvarna Motorcycle:
    650 Terra
    Other Motorcycles:
    Aprilia DD750
    Where is this "purge valve"?
  20. hasenpfeffer Husqvarna
    Pro Class

    Location:
    CO
    Husqvarna Motorcycle:
    TR650 Strada
    It's on the right side just behind the frame rail above the valve cover. It's only on those bikes with a fuel vapor emissions canister.