Bad Piston good compression

Discussion in 'Intake' started by Blasterboy1001, Jan 31, 2018.

  1. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Hey I thought I blew my Piston while I was riding and when I pulled it apart there where nicks in the piston. My friend said that my ring must have broke and done that but my rings are still fully intact. Then I did a compression test and it read 120psi. Now it won't start, please help!
     
  2. speedyslyder

    speedyslyder 2 STROKES RULE Technician Forum Supporter

    Joined:
    Feb 14, 2014
    Messages:
    4,274
    Likes Received:
    821
    Trophy Points:
    178
    Gender:
    Male
    Location:
    massachusetts
    got pics of top end?
    did the engine lock up or just stall?
    120 psi is normal sooo what really happened:)
    electrical?
    fuel ?
    what else have you tried?
     
  3. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    What happened was I went riding, when I was done I pulled into the garage and it was idoiling a little higher than usual so I started messing with the throttle cable and it got stuck wide open. Then I turned the key and hit the kill switch but it still was running wide opened. Then I put it in 2 and dropped the clutch to kill it. Now I can't start it. How do I post pictures?
     
  4. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
  5. blasterbrian

    blasterbrian Member

    Joined:
    Mar 17, 2016
    Messages:
    472
    Likes Received:
    96
    Trophy Points:
    65
    She looks beat buddy
     
    Larry's Shee likes this.
  6. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Ya but it still has good compression so is the piston why it won't start
     
  7. blasterbrian

    blasterbrian Member

    Joined:
    Mar 17, 2016
    Messages:
    472
    Likes Received:
    96
    Trophy Points:
    65
    Im not sure but if i was you id do a top end
     
  8. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Ok that's what I was thinking
     
  9. Larry's Shee

    Larry's Shee Active Member

    Joined:
    May 23, 2009
    Messages:
    7,429
    Likes Received:
    606
    Trophy Points:
    149
    Occupation:
    Unemployed carpenter
    Location:
    Ortskaville, MI
    Exactly. Lots of mechanical damage to it. What was the compression at? What's the head look like ?

    Consider taking cylinder and piston to machinist to measure both to determine wear. While stock cast pistons are good, be aware that when clearance gets to much (wear) they start slapping around and will break causing MAJOR damage. IIRC cast piston needs .002" forged needs .003" .
    I would avoid the temptation to put a new piston in an old hole.

    IF every thing checks out good and you decide to use it as is, at least file the high spots off piston and sand high spots on the head.
     
    blasterbrian likes this.
  10. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Ya I'm getting a new cylinder, head, and piston. There pretty beat up.
     
  11. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Does any one know about the brand Niche Screenshot_20180202-080237.png
     
  12. blasterbrian

    blasterbrian Member

    Joined:
    Mar 17, 2016
    Messages:
    472
    Likes Received:
    96
    Trophy Points:
    65
    Bore and hone oem
     
  13. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
  14. blasterbrian

    blasterbrian Member

    Joined:
    Mar 17, 2016
    Messages:
    472
    Likes Received:
    96
    Trophy Points:
    65
    I mean dont buy that kit aftermarket kits are garbage unless u get vitos 240
     
  15. Larry's Shee

    Larry's Shee Active Member

    Joined:
    May 23, 2009
    Messages:
    7,429
    Likes Received:
    606
    Trophy Points:
    149
    Occupation:
    Unemployed carpenter
    Location:
    Ortskaville, MI
    speedyslyder and blasterbrian like this.
  16. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Ok thanks for sharing that where should I get a stock cylinder and piston
     
  17. speedyslyder

    speedyslyder 2 STROKES RULE Technician Forum Supporter

    Joined:
    Feb 14, 2014
    Messages:
    4,274
    Likes Received:
    821
    Trophy Points:
    178
    Gender:
    Male
    Location:
    massachusetts
    holy S.hit @Larry's Shee posted a link :eek:
    congratulations brother:D;):cool:
    and yes do not buy that kit it will do more damage to your engine and wallet
    then what you have right know.
    im sure you can have a shop bored the cylinder and fit a new piston which is what you need to do
    NOT BUY CHEAP E-BAY CHINESE PARTS THAT WILL NOT WORK.
    YAMAHA IS IN JAPAN NOT CHINAo_O
     
    Markblaster and blasterbrian like this.
  18. speedyslyder

    speedyslyder 2 STROKES RULE Technician Forum Supporter

    Joined:
    Feb 14, 2014
    Messages:
    4,274
    Likes Received:
    821
    Trophy Points:
    178
    Gender:
    Male
    Location:
    massachusetts
    you should also investigate why this damage happened???
    something was getting thrown around in the combustion chamber.
    only time i experience that type of damage was a crank main bearing/case bearing
    crapped the bed sending metal through the top end combustion chamber.
    soooooo why did this damage happen inspect it before throwing money at it peaceo_O
     
    blasterbrian likes this.
  19. Larry's Shee

    Larry's Shee Active Member

    Joined:
    May 23, 2009
    Messages:
    7,429
    Likes Received:
    606
    Trophy Points:
    149
    Occupation:
    Unemployed carpenter
    Location:
    Ortskaville, MI
    :D Thanks Speedy !! :p

    Whatever it was didn't stay long. Check the reeds for lost screw.
    Check exhaust, it could be in there, and get sucked back into cylinder.

    Order of process:
    Measure cylinder
    Purchase piston
    Bore/hone for final fit.
    Don't use cheap gaskets. Yamaha or cometic.< Not cheap
     
    blasterbrian and speedyslyder like this.
  20. Blasterboy1001

    Blasterboy1001 Member

    Joined:
    Oct 7, 2017
    Messages:
    23
    Likes Received:
    0
    Trophy Points:
    32
    Gender:
    Male
    Hey I just got the cylinder done and a new piston and it still won't start
     

Share This Page