Yep, that's a classic sign of fuel dilution in your motor oil. Either your carb(s) are running a bit rich or short distance stop-and-go driving; not letting the oil get up to temp. My car does it too as shown by Used Oil Analysis (UOA).

I've heard you need to drive for at least 30-min each time you do a choke activated cold start. If that doesn't make since for you to do, then change the oil more often.

I get my oil tested by the private label program through Polaris Laboratories as provided by Oil Analyzers, Inc. - link