Page 1 of 4 1 2 3 ... LastLast
Results 1 to 10 of 33

Thread: Fuel pressure?

  1. #1
    Nickeljet's Avatar
    Join Date
    Feb 2007
    Location
    Moss Bluff Louisiana
    Posts
    301
    +1
    2

    Fuel pressure?

    Does anyone know what fuel pressure is supposed to be on a 1996 780 polaris?


  2. #2
    Lake Mead Bum & BTLS Mark starflight's Avatar
    Join Date
    May 2007
    Location
    Boulder City, NV
    Posts
    3,364
    +1
    1
    1.5-2 psi at idle and around 4 psi at wot.

  3. #3
    Nickeljet's Avatar
    Join Date
    Feb 2007
    Location
    Moss Bluff Louisiana
    Posts
    301
    +1
    2
    Thanks a lot. I have 2 lbs at idle but drop to 1 at wot. New fuel pump,pressure tested crankcase at 10 psi for 20 minutes. blocked off return line, no increase. 125 psi compression. All hoses are new and fuel valve bypassed. Any suggestions?

  4. #4
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,327
    +1
    29
    You can rebuild your pentagon fuel pump for cheaper than the cost of a new one. Hopefully you still have it. They have a higher rated output than the round triple pumps.

    Did you change the pulse hose and keep it shorter than 1'?

  5. #5
    Nickeljet's Avatar
    Join Date
    Feb 2007
    Location
    Moss Bluff Louisiana
    Posts
    301
    +1
    2
    Thankx for the pulse hose advice. It is pretty long now. I will shorten it

  6. #6
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,327
    +1
    29
    Shorter the better.

    Also make sure the hose is reinforced. A thin walled hose will collapse under the vacuum.

  7. #7
    Nickeljet's Avatar
    Join Date
    Feb 2007
    Location
    Moss Bluff Louisiana
    Posts
    301
    +1
    2
    The pulse hose is as short as I can get it now. Still only 2 lbs at idle and less than 1 lb at wot. I can block the return line with no affect. The cylinders all have 125 psi compression and no leak downs. I got a new kit for the pentagon fuel pump. Still no differance. Any suggestions would be greatly appreciated

  8. #8
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,327
    +1
    29
    Make sure hose clamps are tight. Check gas tank vents are working.

    Where are you taking your reading from?

  9. #9
    Nickeljet's Avatar
    Join Date
    Feb 2007
    Location
    Moss Bluff Louisiana
    Posts
    301
    +1
    2
    I T off one carb inlet with a 15lb fuel pressure guage. All clamps are tight with new clamps. Even if I block off the return there is no change. All the lines are new and it is the same on a remote tank with a short inlet hose directly in the fuel

  10. #10
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,327
    +1
    29
    Make sure compression is good on the PTO cyl. (weak compression means weak fuel pressure)

    Also check to see if the pulse fitting is nice and tight into the block. My G/F's pulled out with the hose when I removed the engine last fall.

Page 1 of 4 1 2 3 ... LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Installing Fuel Pressure Regulator
    By Red Devil in forum 4-Tec Performance
    Replies: 8
    Last Post: 12-17-2007, 09:19 PM
  2. how to install this fuel pressure regulator?anyone know?
    By novice_4 in forum 4-Tec Performance
    Replies: 24
    Last Post: 05-23-2006, 12:18 AM
  3. fuel pressure regulator
    By Pale Rider in forum 4-Tec Performance
    Replies: 15
    Last Post: 04-26-2006, 06:23 PM
  4. Fuel pressure regulator
    By Pale Rider in forum 4-Tec Performance
    Replies: 3
    Last Post: 04-11-2006, 06:14 PM
  5. fuel pressure
    By Robsauto2 in forum Yamaha PWC Performance (2-stroke)
    Replies: 23
    Last Post: 09-13-2005, 08:14 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
  •