Page 1 of 3 123 LastLast
Results 1 to 10 of 22
  1. #1

    1200 STX-R Engine Issue - Will not idle or rev up...Low Fuel?

    I have been rebuilding my STXR the last month or so. It has 150 hours and was very well taken care of by the original owner. It sat for 2 yeas with a seized pump. In that time, the crank case filled with oil. I have removed the engine to change the driveshaft (seized), replaced all the fuel lines, and replaced the throttle cable. The engine wants to start and not rev past 2200 rpms, and even left idling it will sputter out after a minute or so. This happens no matter what level of choke I am at, what throttle I give it (more throttle dies faster), and if I am on reserve or on for the fuel. There are no warning lights. Things I have checked or changed on the ski...
    1. Fuel Lines and Return Line (I should note that when I put the new lines back, I put them in the organizers glued to the hull...just a thought these might be squeezing the fuel line a bit?)
    2. New oil lines
    3. New WIX inline filter
    4. Pressure tested tank (OK)
    5. Cleaned and rebuilt all the carbs (looked very clean)
    6. Changed the sparkplugs
    7. Ran the ski on various levels of choke
    8. New fuel (50:1)
    9. New 2 stroke oil
    10. New throttle linkage
    11. New battery
    The ski I have set to idle about 1800 rpms, but like I said, any additional throttle it seems to 'bog' and then sputter out. If I restart it, same symptoms. I know I have not done a compression test, but this feels like a fueling issue. As if ir runs out of fuel, dies, and the fuel builds back up for it to run again. All of the cylinders feel the same temperature when it is running. I have checked for spark on all three, and all three are getting fuel at idle (have flooded it by accident).

    Any ideas? I did not take apart the fuel pump when I had the carbs apart...
    Last edited by Mikes1200STXR; 09-24-2022 at 07:34 AM.

  2. #2
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    9,478
    +1
    999
    Does the inline filter have a paper element or mesh?

    Did you check the filters under the needle & seat valves? Clean the fuel rails? Replace the O-rings in the fuel rails and needle valve seats? Did you put the rings on top of the carbs facing in the right direction?

    New throttle linkage??? Why?

  3. #3
    Quote Originally Posted by steve45 View Post
    Does the inline filter have a paper element or mesh?

    Did you check the filters under the needle & seat valves? Clean the fuel rails? Replace the O-rings in the fuel rails and needle valve seats? Did you put the rings on top of the carbs facing in the right direction?

    New throttle linkage??? Why?
    The inline filter is a Wix filter with a paper element. I did clean the filters under the needle valves. Everything was reassembled correctly. It exhibits the same behavior as before the carbs were cleaned.

    I should have said cable, not linkage...I changed the throttle cable because the connector for the oil pump broke off the old cable. Again, same behavior as before I changed the linkage and cleaned the carbs.

    I am thinking the fuel lines are pinched in the factory mount points, the wix filter is a restriction, or the fuel pump is bad.
    Last edited by Mikes1200STXR; 09-24-2022 at 12:17 PM.

  4. #4
    Ah and the plot thickens...apparently cyl 3 (closest to stern) was not firing...see below for the new plugs and the plugs I removed from when it was sitting two years...

    Need to get to the bottom of this first before I fire the parts cannon at the fuel issue...if there is even an issue.

    New plugs...cyl 3 fired briefly it looks like but then stopped


    Old plugs
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Plug 1.jpg 
Views:	46 
Size:	91.2 KB 
ID:	487807   Click image for larger version. 

Name:	Plug 2.jpg 
Views:	45 
Size:	78.2 KB 
ID:	487808  

  5. #5
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    9,478
    +1
    999
    A paper fuel filter is restrictive compared to the OEM mesh filter, but that wouldn't cause the #3 plug to look unused.

    You may have a break in the spark plug wire. Remove the boot from the end of the wire, then try pulling on the wire strands with some needle nose pliers. If you find loose wires, cut the wire back a inch or so (make sure the wires are long enough to reach the spark plug), then re-install the boot.

    Perhaps you have a broken insulator on the spark plug. This gave me fits for a while:



    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Spark Plug, Cracked Insulator 2.jpg 
Views:	46 
Size:	229.7 KB 
ID:	487809   Click image for larger version. 

Name:	Spark Plug, Cracked Insulator 3.jpg 
Views:	47 
Size:	252.3 KB 
ID:	487810  

  6. #6
    Thanks Steve! I will do some more digging. Does the boot just pull off the end? Are the individual spark plug wires replaceable? Or are they part of the whole CDI box?

    I have heard of new plugs being bad...the end may have been unscrewed a bit as well (not sure what to call it, newer plugs have a threaded top you can take off).

  7. #7
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    9,478
    +1
    999
    The spark plug boots screw on. The threaded cap on top of the plug isn't new, it's been around over 100 years. I'm pretty sure it preceded the spark plug boot.

  8. #8
    Thanks, I will take a look

  9. #9
    Well I took the boot off, all seemed OK. Tried turning over with the plug out and grounded, I had spark. Tried the old plug, same amount of spark (I think). The cylinder definitely still is not firing, the plug looks as if it did before. My next step would be to swap plugs 1 and 3 to see if I have the same effect (feeling the pisser tubes for heat). Hopefully #1 stops firing and that narrows it down to the plug...somehow. Really sort of at a loss...is there anything else that would cause it to not fire? The plug is wet when I pull it, so it is getting fuel. Again, same behavior before and after I rebuilt the carbs.

    Previous owner said he did replace the CDI box once...might be that?

    Steve...do you recommend a filter instead of the WIX one I have? I doubt this is a fueling issue at this point.

  10. #10
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    9,478
    +1
    999
    Sounds like you've got gas and spark. Check to make sure you actually have gas in the carb, not just oil. My nephew had a problem recently in which the check valves in the carbs leaked and filled them with oil. This is usually a problem that occurs after winter storage.

    I'd recommend OEM filters or the old SeaDoo filters that can be disassembled and cleaned.

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Fuel Filters.jpg 
Views:	40 
Size:	296.9 KB 
ID:	487829  


Page 1 of 3 123 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Polaris Genesis 1200 (Carbureted) doesn't rev smoothly above idle
    By hookem91 in forum Polaris How To & FAQs
    Replies: 6
    Last Post: 07-09-2019, 02:46 PM
  2. 2003 stx 1100 di high idle issue
    By merlinroad in forum Kawasaki PWC Performance (2-stroke)
    Replies: 6
    Last Post: 07-29-2016, 12:32 PM
  3. Stx 12f 2007 hesistation at low idle after engine is hot
    By Leep in forum Kawasaki How To & FAQs
    Replies: 3
    Last Post: 07-03-2016, 05:28 PM
  4. Idle Issue 1100 STX-DI
    By stx-di in forum Kawasaki Open Discussion
    Replies: 2
    Last Post: 08-03-2012, 08:04 PM
  5. GP 1200 Wont rev up past idle Please Help!
    By CJean386 in forum Yamaha How To & FAQs
    Replies: 17
    Last Post: 07-03-2007, 10:05 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
  •