Heater valve Q

[John Gillis <jgillis@gemini.tcd.ie>]

Hi all,
Can anyone tell me the Tap size and thread type for the heater valve 
that threads into the the top of the cylinder head (low port TR2). I 
know the valve itself is tapered, the threads in my head are a little 
ragged half way down and I would like to run a tap through it before 
fitting the valve.
Thanks
John
-- 
John Gillis
1954 TR2 TS3618. October 1954 (ground up)
2001 Kawasaki W650
Trinity College
Dublin,
IRELAND.