Page 1 of 2 1 2 LastLast
Results 1 to 10 of 17
  1. #1

    Msx 140 new rebuild but wont start plz help

    Hi all,
    Ive often learnt from this site and really need your help!
    I have a polaris msx 140 it turns over does not try to run just goes bang (and i mean bang) after a few seconds, just a massive backfire. this is what i do know:
    engine out of another ski and fully reconditioned 0 hours (injectors and emm original to ski)
    new crank rebuild inc bearings, seals etc by Preben jetski
    two replacement cylinders and all honed
    new pistons rings gaskets etc from Preben
    new tps, cps,plugs, battery (19ah as per service book)
    Fuel pump is working and has plenty of pressure, injectors work and are getting around 18v each.
    all plugs are firing with good spark. fly wheel when 0 at tdc number 1 piston (piston nearest drive shaft) is also at tdc, magnets look perfect.
    A polaris machanic told me carnt be emm due to spark voltages etc and sounds like timing but if the flywheel is in line how can it be out?.
    If anyone has any ideas pl help im mift on this and spent way too much already to just give up!


  2. #2
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,599
    +1
    1,276
    How exactly was that 18 volts at the injector measured?

    If measured from White/Red wire to engine ground with all injectors plugged in, the voltage while cranking should be over 20 volts.

    Backfiring on a Ficht engine often means the EMM needs repair. It could be something else, but often it is the EMM.

  3. #3
    Yes measured with injectors plugged in, however read with analog meter that cost pennies, ill put a digital one on later and post more accurate voltages. Polaris man told me if emm is pushing voltages sparks etc and no engine warnining etc on display then it would be rare for it to be the emm

  4. #4
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,599
    +1
    1,276
    Bad Ficht EMM often still provide spark.

    Spark may be completely wrong timing, or spark with weak injector voltage, or some other EMM internal problem.

  5. #5
    retro's Avatar
    Join Date
    Jun 2009
    Location
    Annapolis
    Posts
    492
    +1
    2
    Like K447 said emm is most likely the culprit. Ive gone through 4-5 Msxs that backfired and all have been a bad emm. I would try another emm if you have access to one. What's your location?

  6. #6
    england mablethorpe lincolnshire, injectors are reading over 21 v, if i throttle it slightly it does fire cuts out then backfires, split exhaust now. i dont have access to emm

  7. #7
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,599
    +1
    1,276
    I would be sending that EMM to DFI for repair, or hunting down another known good EMM with matching injectors.

  8. #8
    Quote Originally Posted by k447 View Post
    i would be sending that emm to dfi for repair, or hunting down another known good emm with matching injectors.

    any one got a emm and injectors, oh and me exhaust has split now so one of those to plz lol. Polaris stress bankruptcy and devorce

  9. #9
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,599
    +1
    1,276
    Why not send your EMM to DFI Technologies for repair?

    There have been MSX 140 parted out by other members, so you just need to look around on the Polaris Classifieds forum here.

    Did you look to see if that exhaust resonator part number is still available new?

  10. #10

    Join Date
    Jun 2008
    Location
    windsor ont
    Posts
    640
    +1
    8
    Quote Originally Posted by morrison View Post
    Quote Originally Posted by k447 View Post
    i would be sending that emm to dfi for repair, or hunting down another known good emm with matching injectors.

    any one got a emm and injectors, oh and me exhaust has split now so one of those to plz lol. Polaris stress bankruptcy and devorce
    what part of the exhaust split?look up the part and post part #

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 03 MSX-140 Now wont start please help
    By higgy in forum Polaris PWC Performance
    Replies: 9
    Last Post: 06-13-2013, 08:42 AM
  2. Help, msx 140 will fire but won't start.
    By johnseil in forum MSX/Matrix
    Replies: 22
    Last Post: 12-06-2012, 01:43 AM
  3. Help, msx 140 will fire but won't start
    By johnseil in forum Polaris Tech Tips and Info
    Replies: 0
    Last Post: 08-05-2012, 08:33 PM
  4. what am i missing? new rebuild, hard to start, wont idle
    By fivespeedsteed in forum Yamaha PWC Performance (2-stroke)
    Replies: 19
    Last Post: 06-25-2012, 05:36 PM
  5. Turns over but wont start
    By tthimlar in forum 2-Stroke Performance
    Replies: 1
    Last Post: 05-03-2008, 04:24 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •