With the head off you can use a regular cylinder head spring compressor. Compress the valve spring, then remove the keepers. Remove the compressor. Push the valve off the seat about 5mm then see if you can wiggle the valve stem side-to-side.
With the valve off the seat, move the valve side-to-side parallel with rocker arm.
The service specification (maximum allowed play) is:
- At the valve stem end, 7.9 thousands (0.0079 inch)
- At the valve head, 1.2 thousands (0.0012 inch)