I recently rebuilt my 09 yz and I put new rings, valves, seals, cylinder and gaskets in it, I lapped the valves seats with the old valves (is this ok, it wasn't on purpose it was on purpose the first time as I wanted to properly seat the valves but then grey racer told me that is a no go so I replaced the valves.) I haven't gotten the head reseated and don't have the money for it either. I wasn't planning on spending $590 on a new head and cylinders originally.... So that hurt my wallet but now hoping I don't have to spend to much more $$$$, so back to the original question, after the 2nd rebuild I put fresh oil and filter in and tried to start it and it fired up in like 30 kicks with ALOT of backfires. Let it idle for 5 min. Went to start it today (5days later) I can't get it to start 50 kicks and a backfire every-other kick. No what?