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Another consideration with most motorcycles is that the transmission adds a lot of more volume and oil to the equation when compared to an engine that has a separate transmission. This means that while it's a good idea to start a bike periodically through the winter, it's important to let the engine run until the whole contraption is up to temperature. This typically takes 20 minutes! This is not a big deal with our liquid cooled sixes but can be a real challenge when there's snow on the ground and you're trying to warm up an air cooled bike. If you've ever seen a oil sight level window that's cloudy or obscured with a white or tan film it's because the bike has been run an put up before enough heat is generated to drive out the condensation. If you can't see through the site glass, can you imagine what the rest of the interior of the case looks like?

Regards

Bill

Works great!! Greetings from Calgary

Calgary Scotland, or Calgary Canada?

Cold starting problems are due to two separate issues. Keep in mind that the choke system is completely independent (fuel wise) from the rest of the carb.
One of these issues is the lack of sufficient vacuum to pull fuel into the choke system. The Choke-Air modification (a restrictor) deals with this. Now there is choke fuel. The engine will fire. The second issue is the idle fuel. Once the engine fires the choke must be reduced or the engine will quickly stumble and quit from being too rich. So we reduce the choke. The choke plungers are now being lowered and there is a reduction of choke fuel but the engine will quit without some jockying of the choke lever. The reason is because the throttle plates are still open too much to create sufficient vacuum to draw fuel into the idle circuit. This is because the fast-idle roller is riding high the apex of the cam. The solution to this is to re-profile the fast idle cam. I have previously suggested this is shouldn't be done,......only because I could envision someone going overboard with their Dremel !
I used my Dremel to remove the apex of the choke cam. About 1mm. Worked perfectly for me.
Now: Full choke - bikes fires quickly and the choke can be reduced and the engine will continue to run because with the modified choke cam, the throttle plates will be closed considerably more. sufficient to create enough vacuum to draw fuel into the idle circuit almost immediately. This also provides a far more linear movement of the throttle plates relative to the position of the choke plungers. The cold start idle is completely manageable because Idle fuel delivery is immediate. The typical cold start popping and farting due to slow and uneven fuel draw is eliminated.
Compare my modified fast idle cam to yours !
The "shiny" edge of the cam is due to de-burring !