I have a 2004 rmz250. It started not to start constantly so i got the valves changed and adjusted. I rode the bike mayb 5 or less times before its not starting again. I have a Bills pipe and wondering if it needs to be jetted or something. I didnt think it would be the valves again beacuse they were worked on just recently. The bike started ok for a few rides but now its starting to get really hard to start again.