EW600 timing case screws

[geomellish]

My engine rebuild is nearly complete (see https://www.douglasmotorcycles.net/index.php?topic=6776.0) but somehow I have managed to lose one of the timing case screws.

This previous discussions on this forum might indicate the raised head countersunk screws are 3/16 x 27 tpi for all the twenties Douglases. However my screws which appear to be the originals, are larger at 7/32 x 25 tpi.  This is another odd size, presumably Douglas produced. Does anyone have any information about this (or indeed have a spare)?  I wondered if I could take a metric M6 6mm, 25 tpi screw and pare it down a little then run a very tight die down it.

Regards, George

[Doug]

George,

Douglas used a 7/32-24 on a few things like the flat head countersunk screws holding the rear plate onto the EW clutch and some suspended 2-3/4hp fuel tanks that used a countersunk, dome head screw. But they kept with the 3/16-27 thread for the timing cover long past the EW era. 

It sounds like your timing cover may have been re-tapped for 2-3/4hp petrol tank screws.

-Doug