Page 1 of 2 1 2 LastLast
Results 1 to 10 of 15

Thread: Sl 750 Pop off

  1. #1

    Sl 750 Pop off

    Hows it boys, took my ski out on the ocean today, when i 1st started her she smoked pretty bad and would only run on 2 cylinders, and the 3rd would come and go, when she warmed up she would go fine. But other than that i have to play with the throttle to get her to plane, if i just stabbed the throttle she would bog out and die. I know the carbs are 100% clean and the fuel is fresh with no water in it. When i rebuilt the carbs about a month ago i never cheaked the pop off pressure as i never had the pop off pump. My question is what is the pop off for the 95 sl 750? as i think it could be this thats causing it to bog, other than that im glueless. Also what sort of 2 stroke oil you guys yous in your premixing and what ratio?


  2. #2
    caliburn's Avatar
    Join Date
    Aug 2012
    Location
    Sister lakes Mich
    Posts
    531
    +1
    12
    Hope this helps, oops sorry for it upside down

    Click image for larger version. 

Name:	IMG_20130415_180533.jpg 
Views:	195 
Size:	63.6 KB 
ID:	298544

  3. #3
    Awsome mate not sure what my needle valve size is tho.

  4. #4
    john zigler's Avatar
    Join Date
    Aug 2006
    Location
    WI
    Posts
    2,545
    +1
    33
    2.0 needle and seat, with black 80 gram springs is stock in a 750.

    I have found actual pop off number typically lower than the Mikuni chart. Be sure to put a few drops of gas in the seat when testing. when you rebuilt the carbs, did you replace needle and seats? did you put the correct springs in? How about your fuel pump, have you upgraded to a triple outlet?

    The other thing I see frequently here in my shop is bad fuel select valves. I do not even test them any more, we simply replace them on EVERY old polaris that comes in.

    Be sure to also look at your gas cap, and filler neck, fuel lines, tank pick up, tank check valve etc. These are problem area's on any older machine.

  5. #5
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,596
    +1
    1,276
    Quote Originally Posted by john zigler View Post
    2.0 needle and seat, with black 80 gram springs is stock in a 750.

    I have found actual pop off number typically lower than the Mikuni chart. Be sure to put a few drops of gas in the seat when testing. when you rebuilt the carbs, did you replace needle and seats? did you put the correct springs in? How about your fuel pump, have you upgraded to a triple outlet?

    The other thing I see frequently here in my shop is bad fuel select valves. I do not even test them any more, we simply replace them on EVERY old Polaris that comes in.

    Be sure to also look at your gas cap, and filler neck, fuel lines, tank pick up, tank check valve etc. These are problem area's on any older machine.
    Do you have replacements for both the two position ON/OFF and three position ON/OFF/Reserve fuel selectors?

  6. #6
    Awsme johny boy, no never replaced the needle and seat, they look fairly new, yes i pulled it apart and it had 2 black srprings and a platinum spring in the pto, so iv pulled it all out and replaced it with the shiney silver, tested them with my mouth and big lungs cant seem to blow threw, i have no pop off pump. Runs heaps better now but havnt water tested it yet tho, i brought the tripple pump off you about 3 months back, replaced my filler cap as it was cracked, done all the fuel lines etc. Them select valves how can you tell if theyr faulty? iv replaced the O rings in it. I sucked on one end and put my finger over both ends of the inlet and i new drawed in any air so i guess it working fine.



















    Quote Originally Posted by john zigler View Post
    2.0 needle and seat, with black 80 gram springs is stock in a 750.

    I have found actual pop off number typically lower than the Mikuni chart. Be sure to put a few drops of gas in the seat when testing. when you rebuilt the carbs, did you replace needle and seats? did you put the correct springs in? How about your fuel pump, have you upgraded to a triple outlet?

    The other thing I see frequently here in my shop is bad fuel select valves. I do not even test them any more, we simply replace them on EVERY old polaris that comes in.

    Be sure to also look at your gas cap, and filler neck, fuel lines, tank pick up, tank check valve etc. These are problem area's on any older machine.

  7. #7
    john do u have any needle seats and springs?

  8. #8
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,596
    +1
    1,276
    Quote Originally Posted by john zigler View Post
    2.0 needle and seat, with black 80 gram springs is stock in a 750.

    ... when you rebuilt the carbs, ... did you put the correct springs in?

    ...
    Quote Originally Posted by luther.douglas View Post
    ... never replaced the needle and seat, they look fairly new, yes i pulled it apart and it had 2 black srprings and a platinum spring in the pto, so iv pulled it all out and replaced it with the shiney silver ... I have no pop off pump. Runs heaps better now but havnt water tested it yet ...

    Them select valves how can you tell if they are faulty? iv replaced the O rings in it. I sucked on one end and put my finger over both ends of the inlet and i new drawed in any air so i guess it working fine.
    Quote Originally Posted by luther.douglas View Post
    john do u have any needle seats and springs?
    Best to telephone John during shop hours. John posts here when he has some time, which will be in short supply soon enough.

    Why did you install silver springs when John specified the Black? Getting the carbs exactly right helps a lot with these engines. A pop-off tester is not that expensive, and can even be cobbled together from simple and inexpensive pieces.

    Engine tune cannot be tested out of the water. Without the load on the impeller the engine is just free revving.

  9. #9
    I installed them 2 days ago i only got johns message this morning, itl only take me 20min to whip them back out and replace them with the black spring. i understand the tuning cheers
    Quote Originally Posted by K447 View Post
    Best to telephone John during shop hours. John posts here when he has some time, which will be in short supply soon enough.

    Why did you install silver springs when John specified the Black? Getting the carbs exactly right helps a lot with these engines. A pop-off tester is not that expensive, and can even be cobbled together from simple and inexpensive pieces.

    Engine tune cannot be tested out of the water. Without the load on the impeller the engine is just free revving.

  10. #10
    john zigler's Avatar
    Join Date
    Aug 2006
    Location
    WI
    Posts
    2,545
    +1
    33
    Quote Originally Posted by K447 View Post
    Do you have replacements for both the two position ON/OFF and three position ON/OFF/Reserve fuel selectors?
    My selects are on/off/res. For the on/off, I run a Y in the line, so it is on/off/on, or you could plug one off, so it is off/on/off

    just a note, it is "my opinion" that there is NO accurate way to test these. I have had muliple machines in the shop here, for tune ups / service, etc, that I could blow throught the fuel select easily, yet the machine ran poor. After replacing the select switch, all problems were solved. I no longer test, I simply replace, as it is easier, inexpensive, and more accurate.......

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. removing the thermostat off my 94 sl 750
    By nickflo7 in forum Polaris Tech Tips and Info
    Replies: 10
    Last Post: 03-28-2013, 04:25 PM
  2. HELP- pop off pressure 95 polaris 750 sl
    By mogyver69 in forum Polaris Open Discussion
    Replies: 18
    Last Post: 07-28-2010, 11:41 PM
  3. 95 SL-750 Snapped brass nipple off in oil line
    By bevelman98 in forum Polaris Open Discussion
    Replies: 11
    Last Post: 08-09-2009, 03:13 PM
  4. polaris 97 sl 1050 pop off pressure
    By sdavid in forum Polaris How To & FAQs
    Replies: 0
    Last Post: 06-03-2009, 11:06 AM
  5. cant get coupler off sl 750
    By redlineracing600 in forum Polaris Open Discussion
    Replies: 8
    Last Post: 02-26-2009, 07:38 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
  •