Hello all, I live in Los Angeles, CA and I just changed my oil recently for my 07 Ninja 250. Before the change i was using Valvoline 10w-40 motorcycle oil and bike ran fine. Ran it to around 5k miles. I ended up having an emergency so i changed the oil with the engine cold. After changing i realized I bought and put in Valvoline 20w-50. After pouring i tried to start it to to let it set in and then pour to the required level. This was the first problem. I put the choke on and it would not start. My bike has always needed full choke to turn on then i slowly decrease it. Most of the time i ride off then decrease it as i go though as im always in a hurry. But the choke was not working at all. Finally managed to get it to work and full choke it was at 3k rpm which is much lower than usual. I then poured the oil needed then noticed that the oil was yellowish/chunkyish and was bubbly. I searched on the forum and that is common apparently. But bike was not starting well and choke wasnt working. Ive managed to have the choke work after revving it manually to about 9k rpm then releasing. When bike warms up it runs amazing and better than before as ive read with 20w-50. But the problem is getting it started cold now. Im thinking of doing a whole oil change again? Not sure what i should do. What do you guys think?