Here is the email be sent me with the video about temperature:
The cold tends to make this bike a little temperamental, so yesterday afternoon while the weather was nice I started it up so that you would have more than just my word to go on that it actually runs quite well, provided its warm out because its supposed to be cold here this weekend. Here is a video of it running, including some revving and close-up so you can hear it running smoothly at all revs and all the lights working etc. Its about 48 degrees out when i took the video. As I was saying, if it's cold when you get here it may not want to run and if it does run it won't idle like it should, temperature is important in an air-cooled twin like this. To understand why, you got to go motorcycle mechanic school for a few minutes.
sorry, but if you're really interested in these kinds of bikes, you'll thank me later. I am a former mechanic at L&M Atv in clymer and that's the only thing that has allowed me to get it into the shape its in. If it gets below 40 you can't rely on it, but so long as it is warmer than that, it runs like a champ and idles fine. My father-in-law has a 1978 Suzuki GS650 and its the same way despite being a four cylinder and his son has a 1979 Honda CB500, its got a radiator, but it also won't run right if it's cold, the point being that it doesn't matter whether its air cooled or not, older bikes don't like cold. The explanation is was that the temperature causes the motor to have a really hard time getting heat into it and the gas has to be hot to detonate completely when the spark plug lights. The unburned fuel is then ejected through the exhaust stroke where the fuel-exhaust mix is pumped out the tail pipe. By this time the fuel may have absorbed enough heat that it spontaneously combusts in the exhaust pipe and thats a backfire. Consequently, even when the motor is firing often enough to run, it will pop and spit and it will struggle to idle and will slowing run slower and slower until it stops with varying quickness depending on warm you were able to keep it while it was parked. I keep it in a heated garage so I usually don't have trouble starting it even on colder nights, but during the late fall-winter-early spring seasons even keeping it warm over night doesn't help because it is still sucking in cold air once its going because obviously the garage door is open or I would die from fumes. When I bought it, the choke didn't work, it was one of the first issues i fixed, and so you had to feather the throttle to essentially hand idle the bike, or give it more gas to balance out the fuel-mixture, it would be a similar situation should you try to ride it in cold weather after getting it going because cold makes the air more dense and so when the intake opens, more air is allowed in than normal causing the bike to run lean: more air to fuel, rather than equal parts. Also cold really affects battery strength so even a good battery, because bike batteries are smaller, they can lose strength in lower temperatures and so the starter won't crank as hard as it normally would which places more "starting responsibility" on the motor firing quickly and being able to get going which it won't do because of the lack of heat in the fuel. Class dismissed haha. Again, sorry for the lengthy explanation, but I figured since its your first bike, you probably would have a hard time believing me that temperature makes such a difference. FYI, I have ridden it from Indiana to Benezet and straight back again and had to stop many times for traffic and climb many hills with a passenger in the middle of august in 95 degree heat. I have never had it over heat, only cold makes a difference. It is a good air-cooled design. So, here is the link to the video, I still haven't fixed the light in the rear which you will see, but I will hope to have it done either today or tomorrow. If you have any questions, about the cold business or the motorcycle itself, I'd be glad to answer them.