Valve Confussion

I spend a better part of the weekend reading up on valves and now I think that I am more confused than when I started.

The center intake valve '07 WR250F is the only one that has ever moved. It started with a 1.78 shim from the show room floor. I have been checking and adjusting as needed, and it is now at a 1.50 shim.

I have read that 10% change is the most you should do and I am obviously past that. Is this truly the case? I have also read that I may need "head work". What exactly does this mean and is this true? Other places I have read that just changing the valves and springs is what needs to be done. Which is the case?

I assume that if I need "head work" that I would send the whole head out and they would work their magic and they would also install new valves and springs. Correct?

If it is only replacing valves and springs, is this something that I could complete? What tools would I need? I have no engine experience beside checking and adjusting the valves.

Any insights would be greatly appreciated!

yes your center intake valve is now cupped or tuliped and needs replacing.

that valve seat needs to be re-cut and you cannot do that at home (well, unless you own a serdi machine). get the tusk valve spring compressor for 39.99 (onsale) and do the dis-assembly yourself. get new springs while you are at it and a new cam chain.

all of the instructions are in the manual.

depending on hours, now maybe a good time for a new piston and rings also.

Thanks! Very helpful explanation. I'll start to look into a shop to recut the seat.

To go off what sunruh is saying. When you replace the valves you need the seats cut to match the valves. If you don't then the valves are going ro wear out very fast. Some places sell heads that are set up and ready to ship but require a core. Some places you ship your head to them and they do their magic and ship it back. Usually the price is better but of course the down time is longer.

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