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.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.
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.