Page 1 of 2 1 2 LastLast
Results 1 to 10 of 19
  1. #1

    Join Date
    Oct 2007
    Location
    Ocon.WI
    Posts
    11

    95 SL750 low power

    I've got a 1995 sl750 that didn't get used last year. After a new battery and new gas she started up fine and seemed to run good. It will only run at about 1/2 speed. Checked plugs and all are sparking. Can you give me an idea where to start looking. It just doesn't seem to have full power. We've got family coming to visit in two weeks and I'd really like to have it running for them. Thanks Jeff


  2. #2
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,570
    +1
    1,272
    Welcome back!

    Click here for the Polaris Service manuals, and lots of other useful info.

    Work through the diagnostics sections in the manual regarding low engine power and RPM.

    Check cylinder compression.

    Have a look through this information, which covers some of the common issues and maintenance items your Fuji engined Polaris may need.

  3. #3

    Join Date
    Oct 2007
    Location
    Ocon.WI
    Posts
    11
    Thanks for your response. I looked high and low for my compression tester to no avail. I must have loaned it out and forgot to whom. I haven't had a need for it in a couple of years. I've got a call out to borrow one . Hate to buy a new one. That's when my old one will show up.
    I dug out the service manual, Clymer Shop Manual. And read some of the trouble shooting stuff and the area on low power. My description of low power may not have been entirely accurate. My son was my source of info. He ran it out for me as he has ridden it much more than I. He said he thinks that it reaches about the same rpm, approx 4400, as the last time he road it. I couldn't find what top operating RPM should be. I found idle rpm, but not high speed. He described it's operation as not peppy. Not quite sluggish, but like it's lagging. We did bypass the fuel water separator, I assume that is what the spin off sight bowl is just after the on off fuel control. I didn't see an in line fuel filter. My hoses must have been changed prior to my purchasing the ski. They aren't the gray ones described in the shop manual. We tried it again with no change in performance. When I line up the comp tester, what should the compression readings be. This is probably enough talk for now.
    Thanks again Jeff

  4. #4
    Lake Mead Bum & BTLS Mark starflight's Avatar
    Join Date
    May 2007
    Location
    Boulder City, NV
    Posts
    3,364
    +1
    1
    You should be able to hit 6200-6400 rpm. I believe the rev limit is 6700
    You need to check compression. It should be around 120psi or so. May be less depending on the cly/ring wear. More importantly, the readings should be within 10% of each other. Make sure when you test compression that the throttle is wide open when testing. It's best done on a warm engine.
    It would also be good to buy a flexable snake light to check the wash pattern on the piston dome to give an indication of how well the fuel is flowing. I'm willing to bet that if compression is ok, fuel flow is your problem.

  5. #5
    Lake Mead Bum & BTLS Mark starflight's Avatar
    Join Date
    May 2007
    Location
    Boulder City, NV
    Posts
    3,364
    +1
    1
    Here is an $8 flex light that will fit through the spark plug hole in the heads to inspect the top of the pistons to check wash. Can be found at a hardware store, Home Depot, or Lowes.
    Let us know what you find.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	HPIM2708.JPG 
Views:	34 
Size:	900.2 KB 
ID:	136336  

  6. #6
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,570
    +1
    1,272
    With the RPM that far below optimal, also check that all three spark plugs are actually firing. They should look the same when you pull them out for the compression check.

    And make sure they are the correct part number spark plugs.

    One thing that sometimes helps improve engine performance is to remove the spark plug boots, and trim about 1/4" off each wire. Then screw the plug boots back on, with new zip ties. The wires can fray at the very end, and make poor contact with the plug boot. Trimming the wire shorter foxes that problem.

    Did you know the Polaris Service Manual is available to you? Just click here.

  7. #7

    Join Date
    Oct 2007
    Location
    Ocon.WI
    Posts
    11
    Good morning
    I'll try your suggestions this weekend. What should I look for regarding the wash pattern. Is there a photo of it. I'm trying to down load a service manual now. Is it different from the Clymer manual I have now? thanks Jeff

  8. #8
    Lake Mead Bum & BTLS Mark starflight's Avatar
    Join Date
    May 2007
    Location
    Boulder City, NV
    Posts
    3,364
    +1
    1
    First pic is good (should have finger nail sized clean areas near the intake ports on the edges of the piston). Second pic is lean. Third pic is a result of running lean.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	wash3.jpg 
Views:	36 
Size:	410.6 KB 
ID:	136392   Click image for larger version. 

Name:	IMG_1769.JPG 
Views:	31 
Size:	565.8 KB 
ID:	136393   Click image for larger version. 

Name:	hole.jpg 
Views:	33 
Size:	186.1 KB 
ID:	136394  

  9. #9

    Join Date
    Oct 2007
    Location
    Ocon.WI
    Posts
    11
    Just picked up my emails. I saw the pics. Will I be able to see that much of the piston through the spark plug hole even with the piston all the way down, or do you want me to remove the head.
    Jeff

  10. #10
    bnasty's Avatar
    Join Date
    Apr 2007
    Location
    Texas
    Posts
    225
    Quote Originally Posted by woodeye View Post
    Just picked up my emails. I saw the pics. Will I be able to see that much of the piston through the spark plug hole even with the piston all the way down, or do you want me to remove the head.
    Jeff
    to me, there is a big difference when looking through the spark plug hole. The lean ones will look like a matte finish, where as the rich/perfect pistons almost look wet. You still should be able to see a bit of wash through the hole with the snake light

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. SL750 low power help!
    By NRW in forum Polaris How To & FAQs
    Replies: 8
    Last Post: 07-17-2010, 10:18 PM
  2. 95 SL750 low power
    By woodeye in forum Polaris Open Discussion
    Replies: 3
    Last Post: 06-19-2009, 04:41 PM
  3. Towing '95 SL750 ?
    By dorf in forum Polaris How To & FAQs
    Replies: 19
    Last Post: 07-20-2007, 11:49 PM
  4. Does a 95 Sl750 have the same number of veins as a 96 slx 780?
    By gvnitup in forum Polaris How To & FAQs
    Replies: 4
    Last Post: 05-28-2007, 12:05 PM
  5. 95 sl750 questions
    By 95 sl750 in forum Polaris Open Discussion
    Replies: 6
    Last Post: 04-16-2007, 05:20 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
  •