# cracked head -yamaha

**URL:** <https://forums.speedlife.net/t/cracked-head-yamaha/194052>\
**Category:** PittSpeed Automotive\
**Created:** [December 6, 2007, 4:13am UTC](https://forums.speedlife.net/t/cracked-head-yamaha/194052 "2007-12-06T04:13:48Z")\
**Posts on this page:** 1\
**Showing post:** 24

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**Author:** ![eurodad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/eurodad/32/5988_2.png) [@eurodad](https://forums.speedlife.net/u/eurodad)\
**Post date:** [December 17, 2007, 4:03pm UTC](https://forums.speedlife.net/t/cracked-head-yamaha/194052/24 "2007-12-17T16:03:58Z")

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> [@PMP takes on the Pump Gas Drags!](https://forums.speedlife.net/t/pmp-takes-on-the-pump-gas-drags/24312/53):
>
> pulled the head-
> 
> piston is cracked off on around the outside  
> about a half inch then another real close to it about a 1/4 long-  
> so you can see the rings in those gaps around the diameter
> 
> ill assume the pieces went into the case- ill be draining that soon.
> 
> why do they crack???

they crack from excessive piston to cylinder play so the piston wobbles/rocks and breaks. basically it was worn the fuck out. and draining the cases will do nothing. the piston pieces will be in the crankcase, not the trannsmission they are seperate on two strokes… pull the motor out and flip it over. see if you can get them all out while flushing it out. otherwise your splitting the cases. i would check the clearances on the cylinder, a new piston may be loose too. might be time for an overbore

i just repaired a 02 rm250 with the same problem. it’s now a 265:boink

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