Page 1 of 2 1 2 LastLast
Results 1 to 10 of 12
  1. #1

    Arrow 780 rough running

    Hello there, wondering if any1 could help please. My cousin has a 96 polaris 780, I recently replaced all 3 pistons as they were fecked. It would not idle so i took apart and cleaned the fuel pump and it was fine so we took it to the water but when you tried to give it a good bit of throttle it would bog down and want to stall so needed to gradually eas it on but once picked up it was offski. we were out for a couple of hours then it started to run quite bad. anything past quarter to half throttle the ski would not go any faster and just start vibrating as if it was chockin for fuel. anyone got any ideas of why this is. thank you very much for any replies. deek


  2. #2
    rustyrider's Avatar
    Join Date
    Mar 2009
    Location
    wilmington, NC
    Posts
    253
    Have you cleaned and rebuilt the carbs? This is a must for any older ski. Also it is a good idea to go ahead and replace all the fuel lines as the start degrade with old age. Each carb has its own filter, make sure these are free of debris

  3. #3
    no mate, i ment to be rebuild and clean the carbs tomorrow but trying to find out as much info as possible to make sure it has to be done because i really dont want to. is it a difficult job mate. do i need any special tools for measuring and setting up the carbs correctly. im quite a capable diy mechanic but after reading a bit of the manual it is quite daunting as it seems are far cry from carbs i have cleaned before plus its not my ski.

    thanks for the help. deek

  4. #4
    BBCaprice's Avatar
    Join Date
    Apr 2007
    Location
    Titusville FL
    Posts
    750
    Cleaning carbs are a must esp if it already burnt down once. Not hard to do-just take your time and one at a time. Everything is behind the diaphragm cover.

  5. #5
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    No special tools needed unless you want to check the pop off. The you'll need a pop off gauge or something equivalent.

    The filters are on the back side of the carbs, make sure you inspect them.

  6. #6
    no probs lads, cheers for the info.

  7. #7
    Mine was doing the same thing. Would not go past 4200 RPM's it turned out to be hitting the rev limter. Starfight told me how to rewire it. The LR-54 module was bad.

  8. #8
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    Quote Originally Posted by chaddyg8 View Post
    Mine was doing the same thing. Would not go past 4200 RPM's it turned out to be hitting the rev limter. Starfight told me how to rewire it. The LR-54 module was bad.
    Good point.

    Was the red light on the MFD blinking?

  9. #9
    Sounds like it could have been running lean and you kept running it like that you could have toasted the engine again. That could be when it started running really bad. Alot of newly rebuilt engines go bad soon again, usually fuel starved. Clean those carbs up good this time and I know on that model Polaris the fuel pump is inadequate you need to upgrade it as I know alot of the rear pistons would fry from fuel starvation.

    Pull your heads and/or check compression make sure you didn't toast the engine. Then go from there.

  10. #10
    Lake Mead Bum & BTLS Mark starflight's Avatar
    Join Date
    May 2007
    Location
    Boulder City, NV
    Posts
    3,364
    +1
    1
    The 96 780 came with the good triple outlet pump.

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. 1200 DI Rough running cold
    By ryand in forum Polaris Open Discussion
    Replies: 9
    Last Post: 10-22-2008, 10:41 AM
  2. rough running until warmup
    By dreww in forum Kawasaki PWC Performance (2-stroke)
    Replies: 1
    Last Post: 05-18-2008, 10:53 PM
  3. 07 160 HO rough running/missing
    By Orrible in forum Yamaha PWC Performance (4-stroke)
    Replies: 2
    Last Post: 03-17-2008, 06:12 PM
  4. 2001 gtx rough running any ideas?
    By baba850r in forum 2-Stroke Performance
    Replies: 5
    Last Post: 02-18-2008, 11:21 AM
  5. VX 110 Rough running
    By Bernie in forum Yamaha Open Discussion
    Replies: 2
    Last Post: 12-21-2007, 09:25 AM

Posting Permissions

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