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2012 KX450 top end rebuild question

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I'm getting ready to reassemble the top end on my 2012 KX450 and noticed in the manual they recommend replacing the washers on the head bolts "or they may allow oil to leak."  How necessary is replacing these washers?  I can't see that any significant amount of oil will get past the bolts, nor does it really have anywhere to go if it does.
Reason I ask is I'd really like to get the bike together and broken in this weekend and if I need to order new washers, I need to do it ASAP.  There isn't a chance in hell that the local dealer will have them in stock.

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I have never done it before and never had any problems. Ive had a top end off a few times and used the same washers. Did you do your cam chain while you were in there?

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I have never done it before and never had any problems. Ive had a top end off a few times and used the same washers. Did you do your cam chain while you were in there?

 

Cam chain still shows to be in spec.  The bike only has 53 hours on it but lots of unknowns and lies from the PO pushed me to replace the piston and rings for peace of mind.

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Unless your in a panic to ride id replace the cam chain. I would also replace the buckets. Cheap insurance!

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Cam chain still shows to be in spec. The bike only has 53 hours on it but lots of unknowns and lies from the PO pushed me to replace the piston and rings for peace of mind.

How'd the piston and cylinder look?

I'm at 70 hours and doing it in a few weeks

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I replaced the piston in my 2015 at around 150 hours of mainly off road/ desert riding, and it looked well enough that I could have ran another 50-100 hours on it. I would recommend replacing every gasket that you pull off, put some gasket sealer on the valve cover gasket ( a product called "The Right Stuff" works great), and replacing the cam chain if you have the top end apart. Never seen a reason to replace the buckets but I come from mainly Yamaha/KTM maintenance.

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I have only dont that once in all my years of 250f topend rebuilds. Now i just flip them over.

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Seen a few buckets break. They are cheap. Def worth replacing. Ktms dont have buckets. Well on my 13 they didnt. That might be why haha

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How'd the piston and cylinder look?

I'm at 70 hours and doing it in a few weeks

 

Both looked great but the piston/rings were replaced as preventative maintenance.  The PO of this bike lied his face off about the actual condition of the bike (and the issues were well concealed) so rather than not know what was going on inside I decided just to swap the piston for peace of mind.

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