Page 1 of 2 1 2 LastLast
Results 1 to 10 of 20
  1. #1
    Mtuned's Avatar
    Join Date
    Aug 2010
    Location
    Orlando FL
    Posts
    724

    Name the piston failure.

    2002 RX DI

    210 Hours..

    OEM PISTONS Stock bore.

    Bought it like this so im not 100% sure what happened.. There was Supertech outboard oil in the tank..

    Looks like it may of been just loose and from heat and stress cracked the ringland.. The plugs were a nice brown color on both cylinders.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	2011-09-26_11-43-10_148.jpg 
Views:	64 
Size:	69.9 KB 
ID:	254376   Click image for larger version. 

Name:	2011-09-26_11-43-31_245.jpg 
Views:	112 
Size:	74.3 KB 
ID:	254377   Click image for larger version. 

Name:	2011-09-26_11-43-15_825.jpg 
Views:	93 
Size:	59.0 KB 
ID:	254378   Click image for larger version. 

Name:	2011-09-26_11-43-23_263.jpg 
Views:	82 
Size:	61.7 KB 
ID:	254379  


  2. #2
    Do the impact marks look like pieces of ring, or did the engine possibly injest something?

  3. #3
    Mtuned's Avatar
    Join Date
    Aug 2010
    Location
    Orlando FL
    Posts
    724
    Stock airbox.. So i dont think it sucked anything in... But possible. Im thinking the ringland cracked due to slapping and then they kept riding it.... Tough to call i guess.

    But the four corner scoring indicates heat seizure as well. Could be running lean on that cyl but i would of expected to see the spark plug to indicate lean condition. I'm stumped.

  4. #4
    Im not as up on 2 strokes as 4 stroke engines, but I have seen a failure similar to that in a 350 chevy drag race engine. The guy had the wrong spark plugs and way to much timing in it and detonated the crap out of it. It actually lifted a chunk of the piston just like in your photo and snapped off a piece of the ring.

  5. #5
    KensGp kenlepack's Avatar
    Join Date
    Apr 2011
    Location
    Ottawa, Ontario, Canada
    Posts
    679
    +1
    51
    that piston definetly was run lean and got very hot pitting the outside and weekening the area above the ring. look up piston wash.

  6. #6
    PoppaRo's Avatar
    Join Date
    Aug 2011
    Location
    Coastal Georgia
    Posts
    21
    very lean detonation "screw it lets ride it" rings gave up next "it still runs ride it" (brown blow by on the piston) crunch "awww it sounds rough." how does the head look? it the rod blued? pics plz!

  7. #7
    If i knew,...I wouldn't ask sea-one's Avatar
    Join Date
    Aug 2009
    Location
    Dallas/Waxahachie
    Posts
    2,340
    +1
    109
    From my view,i would say the crank gave up a thrust washer....imo

  8. #8
    Every adventure comes to an end........ Not Today! wreckingball's Avatar
    Join Date
    Sep 2009
    Location
    San Diego, California, United States
    Posts
    1,347
    +1
    2
    Quote Originally Posted by kenlepack View Post
    that piston definetly was run lean and got very hot pitting the outside and weekening the area above the ring. look up piston wash.
    Yup! - Been There, Done That before I put a fuel controller on my ported GPR

  9. #9
    RumRunnerRon's Avatar
    Join Date
    Mar 2010
    Location
    Portland, Oregon
    Posts
    462
    Wonder what kind of fuel they are putting in that thing as well. Some 2002 DI's still need Premium fuel. The color of the air injectors will tell you. Black=Premium Gray and you can run Reg.

  10. #10
    20 feet Boy's Avatar
    Join Date
    Jul 2010
    Location
    Bend OR
    Posts
    1,257
    +1
    1
    That super tech oil is junk. That is most likely why the motor took a shit. Make sure to put good oil in it if you fix it. You can get away with it in a smaller motor maybe. But a good synthetic oil works the best in the 951 motor.

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. Cleaning case after piston failure? Best approach?
    By snowrunner in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 06-03-2007, 07:41 AM
  2. Piston Failure???
    By beerdart in forum Polaris Open Discussion
    Replies: 16
    Last Post: 03-13-2007, 08:04 AM
  3. Name the Paint
    By pirate33 in forum Polaris How To & FAQs
    Replies: 4
    Last Post: 01-15-2007, 09:33 AM
  4. 65U Group K cylinder/piston failure.
    By Flying Scotsman in forum Yamaha PWC Performance (2-stroke)
    Replies: 14
    Last Post: 10-05-2006, 01:19 AM
  5. Clarifying the SC Failure Phenomenon
    By Jarrett in forum 4-Tec Performance
    Replies: 30
    Last Post: 07-06-2005, 10:14 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
  •