Thanks for the reply's all,
Interesting comments, I did wonder on the valve geometry Hobot, but figured as its a well known thing to do on British twins, or used to be, that it would be OK, I have never read of any warnings to say other wise, the hot cam is something I would never of thought of!, clever stuff.
Pete.v, although the Commando has been off the road for several years, I have owned the bike for, must be getting on for 25 years, so I think my technique is, or rather was!, not an issue, just wanted to make it easier, I think you are spot on with carburettor and ignition, from what I have read, the tri spark would make things a lot easier, I have had an old Boyer, was once a new boyer!, fitted for most of the time I have owned the bike, can kick back at times......
Am afraid Toppy that the Alton kit is just beyond my financial reach, it does look nice!!.
Thanks for the formula TexasSlick, I have not seen that one before, very handy indeed.
Interesting on using larger jets when lowering compression ratio, I have only lowered the compression ratio on one engine, a Reliant 850, which was fitted with an SU, so just a case of altering the jet height there, I know I did re tune, but did not take too much notice to be honest, thanks for your observation on the lowered Atlas compression ratio Jim, so even though it was a very small difference, it was noticeable then, thats good, but maybe sounds like you would not bother in my case?.
I think maybe I am leaning towards using a compression plate and fitting a tri spark ignition when I can afford it, also would like to go to a single carb, I did try a mk2 Amal kit from RGM a few years back, but had a lot of trouble with the slide sticking to the carb bore when shutting down, engine vacuum!!, I have not heard of that problem with single Mikuni kit, but thats another post I think!!.
Thanks all, food for thought!,
John