Cylinder Head work

One of my valves on my 1982 gpz750 has no clearance. I've posts about this before so I apologize, just seeking clarification. I still have no clearance after a valve adjustment, so the manual tells me to cut grind the valve seat and check the valve stem height. The manual goes on to say that if these do not give proper clearance then I need to get a new valve or new head, or both.

Even if grinding the valve stem gives me good clearance, I'm skeptical about how much compression I'll have on that cylinder.
My idea is to simply take the valves along with the head to the machine shop and have the grind all the valve seats and stems, and any other head work I'll need, since I can't simply buy a new head.

My question: is this kind of work possible? Like if I need material added to the head? And if it is possible, would it be worth it? Or am I just going about this all wrong?

The machine shop should be able to do a valve job, at worst they may need to replace a sunken valve seat.
Take it to a shop that does bike heads, or at least an auto machine shop that knows about installed height and shims. A lot of cars have this also.

Wrong ???,sideways maybe.

If you are going to spend that much $$ on a machine shop.
Why not just buy new SS valves and have a good valve job done and forget about it for the next decade or so?

Mike

PS don't GRIND the valve seats, have them cut.
After "grinding" the seats and the valves, it will lower the compression just a bit.

FreakinBike, you may only need what they call a valve "tip", which is grinding off a small amount of the valve stem end, making sure you do not effect the keepers.
A good head-shop would be able to advise.
You always need clearance between the valve and the cam when the valve is closed, otherwise ... you will loose compression and burn the valves. Often grinding the valve face you loose the clearance!
RegardZ.

Before you go tearing into the head have you used the smallest shim available?

How much can be machined off the tip of the valve on a KZ/GPZ? The reason I ask is, a fellow flattrack racer performed a similar machining service on the tip of a Yamaha 500 valve and found out, too late, that he removed all the hardfacing from the tip of the valve! :pinch:

It's not much. A few thousands of an inch. Too much and you suck a valve.

My guess if it's an exhaust valve it's fried, if it's an intake valve the valve is being pulled into the seat and may be cupped. I have seen the seats coming loose on Hiway Patrol bikes exhaust valves but not too much on street bikes. That valve and seat need a real close examination before tip grinding is done.