Results 1 to 6 of 6
  1. #1
    DavidR's Avatar
    Join Date
    Jul 2013
    Location
    Forney,Tx
    Posts
    777
    +1
    45

    Bad day at the lake

    The wife and I took her STX out yesterday for a little ride. In under 15min, motor started surging, max RPMs dropped to 5500. Turned around and started heading back to the marina but didn't make it far. I should have just stopped when I knew there was a problem. Power fell off, and motor locked up. Got towed in by a very nice older couple. Got it home and started tearing it apart. I'm thinking maybe I'll get lucky and just need a piston.....NOT! Burned a hole in #3, guess I have a carb issue. But that's not all folks! Because of the hole and the lean condition, no fuel/oil mix was swirling around in there, so the rod bearing melted to the crank. Damn it! Just bought this one, have only been on it for 80 minutes, now I have to build a motor. The joys of multi cylinder 2-strokes.

    Make note. If you notice a problem, shut it off, get towed in, and get it checked out! I probably could have saved the crank if I had done that.


  2. #2
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    5,008
    +1
    283
    Bummer!

  3. #3
    Banned User
    Join Date
    Jul 2013
    Posts
    424
    +1
    40
    Are you pre-mixing? I haven't had any problems with my big bore GPR

  4. #4
    DavidR's Avatar
    Join Date
    Jul 2013
    Location
    Forney,Tx
    Posts
    777
    +1
    45
    No, the oil injection works fine. This was caused by a lean fuel mixture that burned a hole in the center if the piston.Click image for larger version. 

Name:	image.jpg 
Views:	45 
Size:	81.2 KB 
ID:	314631

  5. #5
    Quote Originally Posted by DavidR View Post
    No, the oil injection works fine. This was caused by a lean fuel mixture that burned a hole in the center if the piston.Click image for larger version. 

Name:	image.jpg 
Views:	45 
Size:	81.2 KB 
ID:	314631
    A lean fuel mixture doesnt this mean oil injection stopped working

  6. #6
    DavidR's Avatar
    Join Date
    Jul 2013
    Location
    Forney,Tx
    Posts
    777
    +1
    45
    No. It means the air/fuel mixture didn't have enough fuel in it and the flame front was VERY hot, causing the hole. When it doesn't get enough oil, the sides of the piston will seize to the cylinder.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Bad day at the lake!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1
    By rotaryfc in forum 2-Stroke Performance
    Replies: 33
    Last Post: 06-20-2012, 07:29 PM
  2. Bad day at the lake!
    By bigboatman in forum Polaris Open Discussion
    Replies: 19
    Last Post: 08-27-2009, 11:33 AM
  3. Bad day at the lake!
    By WICKEDSEADOO in forum 4-Tec Performance
    Replies: 3
    Last Post: 07-12-2009, 10:09 PM
  4. Not too bad of a day at the lake......
    By camar0 in forum 4-Tec Performance
    Replies: 1
    Last Post: 04-23-2007, 11:28 AM
  5. Bad Day At The Lake....:(
    By dereksabolracing in forum 4-Tec Performance
    Replies: 2
    Last Post: 08-08-2005, 08:17 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
  •