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Would it have sat at the dealer for a few months on the showroom floor ??? , if so , its highly possible that they left old gas in it and the Pilot Jet is clogged , causing a extreme lean condition , at 70 degrees it should run within 10-30 seconds without the choke after running with the choke on for that time , then run fine with it off , and be able to idle easily with the idle low , actually at 40 degrees it should run that way , the most you should have to choke it is 1 minute max , even in real cold temps , provided it is jetted properly for the elevation its at (Dealer should have done that) , it has a 20mm carb , so the pilot jet is going to be small , so anything can easily clog it , especially build up from old Ethanol gas
If they are willing (they should be) , ask them to do a service/clean-up on the carb because you feel the carb was clogged when you bought it , and make sure to tell them its been doing this since you got it home , that should get them to cover it , they should not charge you for this , as it should have been taken in back and checked over thoroughly before you took it home once you made the purchase , it should fire right up when finished ....They need to make this right ....