Results 1 to 6 of 6
  1. #1
    skigolfnut's Avatar
    Join Date
    Jun 2009
    Location
    League City TX
    Posts
    1,979
    +1
    33

    pro 785 lost 1/2 power in last race kinda stumped?

    A buddy was racing my Pro 785 here in Texas and the ski had been running pretty good, he went for a warm up run before the next moto and it lost about half rpms,
    we changed the plugs, getting spark to all 3, so no coil problems, power valves were opening good, pulled the carbs and one had a little goo in the pump side, so cleaned all 3 carbs real good, put everything back in and same problem,

    started it up yesterday on the trailer to try and figure it out, idles fine, mid throttle fine, bump it to wide open and it wont go above 6k rpm's, turned jet in, turned jets out,
    still problem, it almost sounded like it was trying to back fire,

    if the stator went out would it cause it to do that?

    any ideas?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	PRO785-2.JPG 
Views:	27 
Size:	130.0 KB 
ID:	309287   Click image for larger version. 

Name:	PRO785-1.JPG 
Views:	24 
Size:	132.7 KB 
ID:	309286  


  2. #2

    Join Date
    Aug 2006
    Location
    Homer Glen Il.
    Posts
    8,702
    +1
    109
    Ronnie,
    check to make sure one if the stinger hoses aren't broken or internally collapsed,or that the flywheel rivits didn't come loose

    first off hows the compression ??

  3. #3
    skigolfnut's Avatar
    Join Date
    Jun 2009
    Location
    League City TX
    Posts
    1,979
    +1
    33
    compression is good across all 3 cylinders,
    mag-170 - center 180--pto 170
    I am getting good water stream out the 3 pissers,

  4. #4

    Join Date
    Aug 2006
    Location
    Homer Glen Il.
    Posts
    8,702
    +1
    109
    Quote Originally Posted by skigolfnut View Post
    compression is good across all 3 cylinders,
    mag-170 - center 180--pto 170
    I am getting good water stream out the 3 pissers,
    you need to check the 1 3/4 hoses going from the pipe to the collector and I've even had acouple of the 3 inch hose from the collector to the water box go bad inside and limit rpm's

  5. #5
    skigolfnut's Avatar
    Join Date
    Jun 2009
    Location
    League City TX
    Posts
    1,979
    +1
    33
    I checked all the hoses real good, squeezed all over them with my hand to check for soft spots, they are solid, the 3" exhaust hose is good,

    I will check the flywheel bolts next weekend,

  6. #6
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    PV valve broke?

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. FS Another Pro 785 lost (1997 part out )
    By american musclecraft in forum Polaris Classifieds
    Replies: 4
    Last Post: 08-20-2014, 01:08 AM
  2. 97 PRO 785 in WV $2500
    By xlint89 in forum Polaris Classifieds
    Replies: 0
    Last Post: 04-27-2008, 12:00 AM
  3. no spark in my pro 785
    By joshxp in forum Polaris PWC Performance
    Replies: 2
    Last Post: 01-22-2008, 02:11 AM
  4. 97 pro 785 runs good out of water but not in
    By bidwell785 in forum Polaris Open Discussion
    Replies: 21
    Last Post: 07-16-2007, 12:48 PM
  5. pro 785 CDI box in 1996 SL780...newbe from PWCtoday here!
    By jcc011185 in forum Polaris PWC Performance
    Replies: 18
    Last Post: 09-24-2006, 09:42 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
  •