2010 450 stopped with a pop


4 replies to this topic
  • fraser

Posted October 28, 2012 - 07:18 AM

#1

Racing last Sunday and on a slowish corner, just starting to wind on the throttle. Engine went pop like a backfire and stopped instantly, no warning noise or rattles or anything . Went to kick it and it was very stiff so I didn't try again.

Took it apart today and head, cams, cylinder, piston etc all look fine. No dropped valves or anything like that which was a relief. Big end of the conrod is seized. Crankshaft looks blueish either side of it. What's the procedure here and what will I need to replace, not had anything like that before? Oil, and water levels were clean and good. What would have caused that?

Thanks

Edited by fraser, October 28, 2012 - 10:30 AM.


  • grayracer513

Posted October 28, 2012 - 07:49 AM

#2

I'm just guessing, but if you meant to say that the crankshaft is bluish on either side of the rod, that's normal. Part of the manufacturing process.

Nevertheless, the crank needs to be replaced or rebuilt. An oiling problem is the usual cause, but the rod bearing can also seize if the roller cage breaks and allows the rollers to skew off track on the crank pin and become wedged. Carefully inspect the oil pump and the passageways involved.

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  • fraser

Posted October 28, 2012 - 10:31 AM

#3

Will do, I did mean crankshaft.
Thanks

  • crf450319

Posted October 28, 2012 - 05:24 PM

#4

FYI, a new OEM crank including both halves, the pin, the conn. rod bearing and the connecting rod can be had for $295 + shipping. If it's going to cost you $200 to have yours re-built I'd just as soon put an entire new unit in there. But, some people might want to go the re-build route... Just thought I'd throw that out there.

  • marv02

Posted October 29, 2012 - 04:44 AM

#5

2nd that if a complete new crank is not that much more money for it I had cranks rebuilt and had issues with them after I never had any issues with a new in the box complete crank.

Clean the oil pump and all the oil passagway very very good last thing you want to do is rebuild the motor just to find out there was junk it the motor still and toast the new one on the first time out.

FYI, a new OEM crank including both halves, the pin, the conn. rod bearing and the connecting rod can be had for $295 + shipping. If it's going to cost you $200 to have yours re-built I'd just as soon put an entire new unit in there. But, some people might want to go the re-build route... Just thought I'd throw that out there.







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