Help, The choke on my 99 YZ400 wont stay out. It will stay out for a sec, but as soon as the bike lights up it snaps shut. My buddy's 98 wr400 does the same thing only his wont stay out at all. Is it just the choke shaft or is there some thing else that is causing this. I saw that the choke assy is only like $15 but I dont know if this is the problem. Any ideas? Also what is the best bar mounted hot start unit. My stock one took a poop. If I am replacing it I might as well upgrade it.