That wasn't the case...The engine specifications and carb settings for WD M20s are the same as for civilian models...
There are no meaningful performance improvements that can be gained without engine modifications....Ian
email (option): ian@wright52.plus.com
Roger that Ian,
Yes I read your interesting article in the tehnical section. I haven't got the tools or knowledge to under take such an upgrade, and the very low mileage I will be riding wouldn't warrant that anyway. But maybe one day !
When you opened the frottle up on Omaha beach and acheaved a high speed, was that with your up graded M20 ?
Oh .... I need a ball bearing for my clutch rod arm (that makes contact with the long rod that runs through the clutch) is there anywhere local in the west that sells them ? I can't find what size I need
Cheers
Mark 
email (option): towersmark84@yahoo.co.uk
If you mean the one in the clutch arm I probably have one...E mail me about it to remind me...Ian
email (option): ian@wright52.plus.com
There are no meaningful performance improvements that can be gained without engine modifications....Ian
I assumed that Mark was referring to the attempted wartime fuel saving measures rather than performance improvements, if they did attempt this with the M20 the carburetor must have been how they did it.
I think I read somewhere (or a man in the pub told me) that some OHV motorcycles had a thick washer placed under the barrel to reduce compression either for this reason or to slow down the average speed, was it Matchless or Ariel?
Rob
email (option): robmiller11(a)yahoo.co.uk
There are no meaningful performance improvements that can be gained without engine modifications....Ian
Well yes and no
By accident I ended up running a 930 concentric on my Wm20.
Made a massive difference to the performance
Also made a massive increase in the fuel consumption.
I now run a 626 nicked off a WD 40 and jetted almost the same.
With this fitted I can outrun any M20 wearing a type 27 in both acceleration and absolute top speed, just so long as we are headding towards fuel stop.
The magic pudding was a childrens fiction .
email (option): bsansw1@tpg.com.au
I think I remember that too! But the parts list states "Quantity required one" I think they are about 7 thou thick. Maybe you have the option to fit two and reduce your compression by 1/529th 
Ron
email (option): ronpier@talk21.com
The clutch arm ball bearing isn't 1/4" diameter...and the pushrod didn't have a 1/4" ball bearing anywhere...The pushrod was one piece...
However, people do add a ball bearing to solve the worn pushrod problem rather than fitting a new rod...Ian
email (option): ian@wright52.plus.com
['any small ball bearing should do..']
Not really the case if you want to do it correctly and make it function as intended....
The bearing in the clutch operating arm is fitted to the arm and then the hole is swaged over slightly to stop it coming out...If you examine a NOS arm you will find the ball it entrapped and won't come out of the arm...
The original ball, from memory is 5/16" diameter...Using a smaller ball means it will not necessarily contact the pushrod correctly as it is not held centrally to the rod, which it is if the correct ball is fitted...
As stated in my last post and to avoid any confusion there is no ball relating to the pushrod other than the one in the operating arm and the one in the clutch pressure plate......
Also, both ends of the push rod should be flat..If it is not the ends are worn...
This may be caused by incorrect setting of the clutch cable free movement,the ends of the pushrod being ''over tempered' during the hardening process or simply through over extended use...
The ends can usually be machined flat and the rod rehardened and tempered if it is not too badly worn...The slight reduction in length can be taken up with the clutch arm adjuster screw...
Alternatively make a new rod of the correct length from 1/4" dia. silver steel rod...Ian
email (option): ian@wright52.plus.com