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Broke a valve, need a head

By AnthonyH,
in CRF450R/RS/RWE & RX

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AnthonyH

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Bike had less than 10 hrs since rebuild. Exhaust valve broke and embedded itself in the head. I'm not sure why this happened maybe it was valve float? I'm not sure of the brand, but the valves are steel. I'm going back with oem. I have all the parts to rebuild, but the head. It's on a backorder from Honda. Anyone know where I can get a head for 07/08?

Here is the damage.

20170708_231659.jpg20170708_231711.jpg20170708_231630.jpg

 

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Shawn_Mc

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The whole reason I suggested it is that he'll only have about 110 bucks more into the head than if he was to piece part an OEM together using all new Honda stuff. And he'd start out with better than stock stuff. By the time you buy the tools (if you dont have them) to properly assemble the head, its actually cheaper.

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Jeff@bigborethumpers

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Those are kibblewhite valve springs and retainers, Id guess that those are kibblewhite valves. Check out Bigborethumpers.com we offer new OEM heads with stainless steel valves in them starting at $549.95 for the 06 head and $575 for the 08 style head. We also offer the newer heads just let me know what you need, and I can get you a price. We also offer porting if that something you are looking for. 

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AnthonyH

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I first looked at Fastheads and bigborethumpers, but decided to go with oem. I have all the tools to do the job. I did my 250x before I sold it. The only thing I can't figure out is why it happened in the first place. This is a low hour bike that was rebuilt before I bought it because it sat in storage 7 years with gas and fluids left in it. Kibblewhite valves are not supposed to break. That's why I am going back with oem, never had this problem with oem.

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Grand Master

Shawn_Mc

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1 hour ago, AnthonyH said:

I first looked at Fastheads and bigborethumpers, but decided to go with oem. I have all the tools to do the job. I did my 250x before I sold it. The only thing I can't figure out is why it happened in the first place. This is a low hour bike that was rebuilt before I bought it because it sat in storage 7 years with gas and fluids left in it. Kibblewhite valves are not supposed to break. That's why I am going back with oem, never had this problem with oem.

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No valves are supposed to break, but they break every day. If the timing chain jumped a bunch, the timing could get retarded enough to hang the exhaust valve long enough to have the piston kill it.

Did the bike have the standard OEM tensioner?

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AnthonyH

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Yes, oem tensioner and it seems to be working fine. That was also my first thought, but the other valve should have some mark from piston and it doesn't. Is there really that much of a failure rate on stock tensioner? Should I go with manual one, if so, which one? Seems like a manual one could get you in trouble if you don't stay on top of it and keep tension correctly.
As for the head and online retailers, you can buy one, but it will be backordered. All the Honda warehouses are out. I have one on backorder with Babbitts for a month now. Called several other large Honda retailers and same thing. Local Honda shop did a search and found nothing. I was hoping someone knew of a place that would have one in stock.

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Jeff@bigborethumpers

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8 hours ago, AnthonyH said:

Thanks Jeff. I already have all the parts to build the head so I am just looking for the bare head. Do you sell the 08 head without valves?



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All I have is a ported one. If you wanted that one I could do it for $700 but other than that Im with the rest of the world waiting on honda. 

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