my 86 dl (carbed 1600) will NOT start when the ambient tempature is 40F or less. when the weather is warm it will start aftercranking the statrter for a long time but sometimes starts right away. once stated it runs fine. i have cleaned and rebuilt the carb have a rebuilt distributer and a new fuel pump and filters. i am perplexed and befuddled.

Is the choke working? That sounds like the most likely problem. Check the linkages and make sure they're right.

yes the choke is working

bumparu

coolant temp censor maybe,