I have a 2000 Yamaha 2 cylinder 15hp 2 stroke outboard that wont run unless the choke's on at least half way, whether at idle or at full throttle. The motor has sat for about 2 years but is in good condition. I have had the carb off and diassassembled it and it looks OK. Fuel appears to be flowing to the carb OK. I have also changed the fuel. I would appreciate any suggestions. Its driving me nuts.
My 1999 Yamaha 2 stroke is doing pretty much the same thing. Starts easy and runs if you keep the choke part way out. I'm going to try the spray thing. I still have a little Sea Foam or Sea Spray, whatever it's called and I'm going to put a little of that in the fuel. It's a real pain taking it off the bracket of a boat in the water to take it in for service.
Very little doubt that you have a fuel restriction, most likely in the carb. It needs a good soaking (overnight for me) and blowing out with air before reassmbling. Those have small passages and I usually wash out with very hot water and then blow out. NOTE: Spouses tend to get very ill over washing out in the kitchen sink.