I have a Suzuki 1400 intruder that i bought last summer that refuses to start below 50 degrees F. I'm not sure if this is just a function of a large hard to start engine or something else. I also have a problem getting much gas/not enough air to the cylinders as my spark plugs soot up every 2-3, enough that I notice it when I pull them out. Does anyone have any ideas?  

I think i have the same problem. I rejetted my bike and the rear cyclinder seems too rich. I notice when i am stopped for a short time, then start out again, i get some smoke from the cyclinder. Plugs in the front cyclinder are good but rear appear to be getting too much fuel. I changed jet size again and it still happens. Am also getting slight popping on decel from the rear cylinder too. Doesn't make sense. If i richen the mix to eliminate the popping, the smoking gets worse and plugs get wet with unburned fuel. I have wondered about being able to introduce more air to the mixture in that one cyclinder.  

I know of a fix for the problem with cold starts.  You can buy a can of ether for 2 bucks at any autopart store.  A small spray into the air intake should get it running.  I had a toyota supra that had the same problem.  It's not a very permanent fix but it will work if it's not under 50 very often where you're at.  

I am back again. I solved my problem. My choke cable was in a bind after doing my carb work and the choke (fuel enricher) was stuck. Now I don't get the smoke in the one cylinder anymore either.