Page 1 of 2 12 LastLast
Results 1 to 10 of 15
  1. #1

    Join Date
    Oct 2015
    Location
    Gatineau,Quebec,Canada
    Posts
    6

    2003 MSX140 overheating.

    Just installed a brand new engine from SBT, cannot run it for more than 1\2 a mile and it shuts down and the engine is very hot. I have to wait a few minutes and it will restart and do it all over again.

    what could be the problem ?? anyone have an idea.


  2. #2
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,681
    +1
    196
    Check your plumbing.

  3. #3
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    39,391
    +1
    1,746
    Welcome

    Make sure you have not swapped the water feed and water exit hoses for the engine.

    The hose from the thermostat housing (water manifold bar on top of the engine) goes directly to a hull exit fitting. It does not go down to a jet pump fitting low in the hull on right side of the pump tunnel.

    The water feed from the jet pump, down low on right side, goes forward under the engine and eventually feeds into the big exhaust pipe, very low and left side of engine.

    Did you remove all the water hoses from the hull when the engine was out?

    Have you done the other recommended repairs, especially the reinforcement of Ficht fuel pressure regulator?

  4. #4

    Join Date
    Oct 2015
    Location
    Gatineau,Quebec,Canada
    Posts
    6
    The hoses were not removed from the hull\jet pump. I've checked my thermostat and starts opening at about 150f and is fully opened at 160f, is that ok? I dont know what you are saying about the fuel pressure regulator, is it a part to replace or to modifie? By the way, i have had the MSX for about 6 years and besides the hull bearing a few times, nothing else has ever gone wrong, it has 222hrs on it.

  5. #5
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,681
    +1
    196
    Check the area of the pump where the cooling water originates, there's a screen there that if clogged will not allow water to flow into the cooling system. (The pressurized water from the pump is what cools the engine, routed from the pump nozzle, through the plastic tube, and up into the engine)

  6. #6
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    39,391
    +1
    1,746
    Quote Originally Posted by danguenard View Post
    The hoses were not removed from the hull\jet pump. I've checked my thermostat and starts opening at about 150f and is fully opened at 160f, is that ok?

    I dont know what you are saying about the fuel pressure regulator, is it a part to replace or to modify?

    By the way, i have had the MSX for about 6 years and besides the hull bearing a few times, nothing else has ever gone wrong, it has 222hrs on it.
    The stock thermostat should open at around 143F. Yours may be opening slowly or perhaps the measurement method is not accurate?

    If the engine is truely overheating then it is possible for the temp sensor on the exhaust to be cooked and need replacement. If it is providing inaccurate temp readings to the EMM engine computer the engine will not run quite right. This is separate from any overheat warning on the dash. Not a cause for the overheating but a knock-on side effect of an overheated engine.

    There is also a service bulletin for adding a rubber bumper to protect the exhaust temp sensor wiring. The plastic exhaust tube can press on the sensor and damage the wires.

    The stock fuel pump has a pressure regulator mounted inside the top of the pump assembly. It is very common for the mount to work loose and allow the regulator to fall into the bottom of the fuel tank. The engine will still run but the engine will be at great risk of lean burn piston damage.

    Reinforcement of the mounting for the Ficht fuel pump pressure regulator is considered mandatory. Repair method using an NPT-27 thread tap and hose barb is outlined elsewhere on GH. Click my signature links, look in the Ficht section.

    For your overheating problem, review the entire water flow path, from the jet pump inlet mesh screen to the hull exit fitting after the thermostat housing. Somewhere in there may be an incorrect hose hook up, kinked hose or other problem.

    Beside the thermostat there is a pressure bypass spring and plastic tip in the same housing. If the tip is worn then it should be replaced. Inspect the housing for wear grooves.

  7. #7
    Resident electronics hacker UnityRacing's Avatar
    Join Date
    May 2007
    Location
    Suffolk, VA
    Posts
    1,442
    +1
    28
    Part of the problem is that SBT royally screws up the MSX engines. They get rid of the Nikasil coating on the cylinders, and replace with iron sleeves. The heads are not MSX spec heads, but standard 1200 DI heads. They also weld shut the cooling restrictor plates on the heads.

    An SBT MSX engine is about the worst thing you can do for your ski. I wouldn't trust them to rebuild my lawnmower.

  8. +1 by:


  9. #8
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    39,391
    +1
    1,746
    Quote Originally Posted by UnityRacing View Post
    Part of the problem is that SBT royally screws up the MSX engines. They get rid of the Nikasil coating on the cylinders, and replace with iron sleeves. The heads are not MSX spec heads, but standard 1200 DI heads. They also weld shut the cooling restrictor plates on the heads.
    ...
    The SBT rebuilt engine should not rapidly overheat, despite the non-Polaris rebuild methods. Something is wrong with the cooling system, somewhere.

  10. #9
    Resident electronics hacker UnityRacing's Avatar
    Join Date
    May 2007
    Location
    Suffolk, VA
    Posts
    1,442
    +1
    28
    Perhaps they welded too much of the heads and blocked coolant flow. I unknowingly bought an SBT 140 engine and was shocked at the craptastic work they did to it. If I remember when I get home I'll post some pictures of one of their 'worked' heads.

  11. #10

    Join Date
    Oct 2015
    Location
    Gatineau,Quebec,Canada
    Posts
    6
    Thanks for all of your answers,

    I will check every thing thorougly. One thing i did not mention is that i am able to run the engine with a garden hose hooked up on the cooling rail and it can run for as long as i want it too and it does not over heat. Btw, my old engine blew the #1 piston skirts to a shred but did not seize and it did not overheat either, but it had been Noisy all summer long.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2003 msx140 - early or late build
    By fusion900 in forum MSX/Matrix
    Replies: 10
    Last Post: 10-26-2008, 11:47 PM
  2. 2003 msx140 -Touch up Paint
    By fusion900 in forum MSX/Matrix
    Replies: 0
    Last Post: 10-26-2008, 02:55 PM
  3. WTB-EMM for 2003 MSX140
    By ifixcars in forum Polaris Classifieds
    Replies: 5
    Last Post: 05-20-2008, 10:17 AM
  4. Replies: 77
    Last Post: 11-24-2007, 11:42 PM
  5. 2003 Msx140
    By Scott M. in forum Polaris Open Discussion
    Replies: 2
    Last Post: 11-24-2007, 11:19 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
  •