ok... couple things
the website saying to put half a 16oz can in your motorcycle tank is exceeding the recommendations on the side of the can: 1 ounce per gallon. The only time Ive heard of people having trouble with seafoam and other carb cleaners is when they dont follow the directions on the can written by the people who make the stuff.
about starting the bike: what are you doing with the choke when its cold?
the normal sequence is:
choke all the way out
crank the starter with zero throttle applied
when the engine fires you can burp it just a bit after you let off the starter
immediately push the choke in till it idles down normally, about half way in
check your lights and mirrors and all your gear, push the choke in a bit more if the motor sped up, then ride off
when you get about 1/2 mile down the road push the choke in all the way.
There is no procedure for starting the bike up and letting it sit there half choked warming up. If you wanted to let the bike sit and idle you would have to match the choke position bit by bit as the engine heads warm up. There is no need to do that.
If you get the bike to start, ride it. Once you have the throttle off zero the choke is no longer doing anything significant, just making the bike run a little bit rich. By the time you get half a mile down the road the bike should be warm enough for zero choke.
Before you tear the carbs apart, if its running it usually helps to put seafoam in your new gas. If the jets and ports are letting fuel thru (if the engine is running at all) then the carb cleaner will do its work as it flow thru the carb. Its $8 a can and worth a shot. The only time you really need to take the carbs all apart is if they are completely plugged with jello, and the engine wont run at all.
Also since you think the bike is running well, except for the choke business, the carbs cant be gummed up that bad. Go for a full tank of gas with 4oz of Seafoam and dont be shy about cranking the throttle open when you can, and then see how the cold start works after 200 miles.
Last edited by KCW; 12-06-2018 at 09:28 PM.