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Discussion Starter · #41 ·
The seats are actually hardened inserts pressed into the head, not the actual aluminum. They are replaceable at around $5 a piece (then you need someone that can press them in safely.

the big issue is once you are replacing seats, usually you’d replace valves, but they’re like $100 a piece! Then there’s the valve guides... and oh yeah, you really need to replace the guide seals. That makes parts, alone upwards of $2000....BEFORE you have someone lay hands on it to press in the seats and guides, seat the valves and ream the guides.

Flyers28, If it were me, I’d find a machine shop that would look at the head and determine if they could do a 3 angle grind on the seats and grind the stems, and replace the valve guide seals. It might cost $200-$300. But it would be better than chancing it on a used head and way cheaper than a 100% refurbishment. The main issue will be finding a shop that would be able to deal with such small valves. If you do happen to have a motorcycle race bike builder near you it might be worth getting a price from them, too. But I’d suspect it could be almost as costly as all the new parts.
Yea, its been hell trying to find a machine shop that works on motorcycle heads. Out of the dozen shops I reached out to one said they don't normally but are willing to look at it, but also said the valves are likely trashed and they can only replace. We shall see. Hopefully I can get it to them on Friday before they close. Most shops are telling me I probably have some valve float going on and the valves are trashed. I don't know of any motorcycle machine shops near me either and certainly no race bike builders. I think I'll just have to find one and ship it out to them. But more and more this is looking like game over sadly.

If anybody knows of a motorcycle machine shop they trust, let me know so I can reach out to them and look into sending it out.
 

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What are the risks in continuing to use the same valves... since they represent the bulk of the cost?
Over time, wouldn't the old valves beat the new seats into conformity for a decent seal?

Sounds like they're trying to sell you valve springs also. But they're obligated to mention every little possible thing that could be wrong. I pulled the head off my car with the camshaft still installed. You can do your own visual inspect of the valves and the seats after taking the head off. Should be able to borrow the valve spring compressor tool from the parts store and disassemble the head your self. Though it didn't happen with me, that car's engine head was notorious for dropping valve seats. So I had the machine shop premptively replace the seats even though I was taking it in to repair a crack in the head.
 

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YZFR6... ooodles of HP
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The valve is far stronger then the seat regardless of its material choice. Lapping a used valve to a used seat can help without doing a full grind rebuild.
 

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UR B-hind Da 8 Ball
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You’re in PA, right? Contact Anthony at Bauce Racing. I know he doesn’t do head work. But I bet he knows who does in your area.
 

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Discussion Starter · #46 ·
So according to Ant, it's $500 to resurface and do a valve job. Now whether that's 500 and job done or 500 plus the cost of valves and kit I am not sure. That detail might come later. But assuming it's $500 and job done I got decisions to make. Drop $500 and sell a complete bike (after 1 last season of course) or cut my loses and go through the hassle of parting it out. I'll try and remember to update this thread with whichever route I go just to put an end to this.
 

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How many 'one last seasons' have you had thus far? Might be something else to consider. If you already have another moto then yeah, use what you already bought. Personally I have no issues with sticking with what I already have; so long as it'll continue to work over the long term. Part prices and availability are only bound to get more ridiculous and even scarce... so there's that factor as well. Unless you're Cuban or something, one can only maintain a machine for as long as the parts are affordable/available.
 

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Discussion Starter · #48 ·
How many 'one last seasons' have you had thus far? Might be something else to consider. If you already have another moto then yeah, use what you already bought. Personally I have no issues with sticking with what I already have; so long as it'll continue to work over the long term. Part prices and availability are only bound to get more ridiculous and even scarce... so there's that factor as well. Unless you're Cuban or something, one can only maintain a machine for as long as the parts are affordable/available.
By one last season i mean with this bike. Ive had my eye on the MT-09 for awhile now. So its always been the plan to sell the R6, just had to wait to accumulate the funds. And I wouldn't have minded one more season with the R6 to save a few more bucks which was the plan before discovering this little glitch. Add to that, the availability of the 2021 model (the one yamaha finally got right) still being scarce means im still a little eager to fix up the R6 and still be able to ride this year.
 

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Discussion Starter · #49 ·
So the valves definitely pounded their way into the seat. After speaking with someone at the shop I've decided to throw in the towel and part the bike out (ugh). He could have grounded down the valve stem tips but we both agreed it was just a band aid and would not fix the overall issue. It needs new seats and thus new valves. Sad days. Thanks to all those that helped me out.
 

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Why does it need new valves? What are the consequences of just replacing the seats? Wouldn't the old valves eventually pound-out the new seats for a decent seal?
 

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YZFR6... ooodles of HP
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Bummer. Are the valves bent?
 

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No answers = personal inspection = keep valves.
 
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