Just installed Athena BB kit....problem!!

3 replies to this topic
  • SCRC John

Posted September 17, 2010 - 08:12 PM


So I install the 478 Athena kit in my WR450. Everything goes good. I get everything together. I turn the engine over by hand. She is good!:banghead: I get the spark plug in and turn the engine over with the starter and I hear this loud knocking..:ride:

I remove the plug. Turn the engine over with the starter again....no knock. Am I doing something wrong? I am running the same plug as before. NGK9EK.

Has anyone else came across this issue. I've searched but found nothing.

  • CanadianWR450

Posted September 18, 2010 - 04:11 AM


you have the exhaust, and intake/breather installed right?
(They make some funky sounds without the air filter, exhaust installed)

Put the plug back in and SLOWLY kick it through a cycle with your foot and see if it feels normal, and not binding up.

You may want to double check your timing as well

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  • miweber929

Posted September 18, 2010 - 04:39 AM


Has nothing to do with the plug but everything to do with the fact the plug in creates compression.

Recheck your piston, rod and ring installations as well as timing, cam chain tensioner and valves.

I imagine something isn't "tight" when under a compressed load. Maybe piston pin bearing?

  • Birdy426

Posted September 20, 2010 - 05:06 AM


Check torque on the cam cap bolts...even 10 in-lb over spec will cause a knocking sound (voice of experience!)


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