Hey guys I have an 04 preddy 500,I'm having trouble getting it started 99% of the time. I HAVE to hold my hand over the carburetor until it spits back some gas then remove my hand and it tries to fire sometimes it will start up and run and other times I just have to repeat those steps. I've cleaned the carburetor thoroughly, put new piston rings in it, and a new choke cable and just cant figure it out. Would anybody know what it could be? I know I set the timing right, i have a sneaking suspicion it's the valves.