blew the crank

• blew the crank
  Posted by Jsmitty42 on 11 Jan, 2014 15:35
• Well I rode less than a mile down the road to my buddys house. I pulled in, shut off my quad and we sat around for about 20 minutes. When I went to start it, it was seized  so i got it home took the top end off and the piston was all messed up at the top. It was like chipped in a lot of places and so was the head. What does that mean?
• 
  
• #1 Reply
  Posted by BadMoonRacing500 on 11 Jan, 2014 16:16
• Pics of piston and head?
• 
  
• #2 Reply
  Posted by Rider414 on 11 Jan, 2014 20:03
• It pretty much means you blew it up.
  
  
• 
  
• #3 Reply
  Posted by BadMoonRacing500 on 11 Jan, 2014 20:16
• Quote from: Rider414 on 11 Jan, 2014 20:03

  It pretty much means you blew it up.
  
  
  

  Thank you Mr. Obvious,  I think he want's to know how it blew up? My first thought thrust washer or bearing, but if he held it wide open for a mile it might be melted piston chunks.
• 
  
• #4 Reply
  Posted by Zuki250 on 11 Jan, 2014 20:37
• Im guessing cold seize.  Not enough lub. Piston started to peel from friction causing more friction.it wasnt enough to seize while running but would have.
• 
  
• #5 Reply
  Posted by LT500Kid on 11 Jan, 2014 23:14
• Take the jug off and inspect further I'm assuming you only pulled the head for inspection
• 
  
• #6 Reply
  Posted by ZillaFreak on 12 Jan, 2014 07:23
• What premix were you running? Was it 20:1? If not, you need to mix at like 15-20:1
• 
  
• #7 Reply
  Posted by Stpltn250r on 12 Jan, 2014 09:41
• How old was the piston? Bore could have been loose and piston came apart. Were you running it hard to your buddies house? Could have detonated on a long pull and suddenly pulling in the clutch in over rev.
•