I just got a used s40 boulevard. I just bought a battery for it. When the choke is pushed in, it starts up fine. If I try to start it with the choke all the way out, it won't start. I thought you need to have it out when starting it? I let it warm up for a few minutes and sometimes it just dies after 3 or 4 minutes. I hear it struggling and will give it some throttle but sometimes it's not enough. Earlier today I rode it for about 15 minutes and as soon as I slowed down to first, it died... I don't know how to use the choke on this bike and I'm not sure why it keeps dying?