Hi guys, I'm kinda new here, been lurkin around a lot reading before I had to ask for advice. So I've been rebuilding my yz426f 2001 from bottom up. I guess it skipped a toothe or dropped a valve and the piston slamed on the valves, choping some of them completely off. I bought a used 02' head which included everything, Ti valves, springs, camshafts etc. Did the bottom end, bought new piston and rings, installed everything. Checked the clearances, the exhausts are .25 and the intakes .15. Cleaned the carb, got new gas, new spark plug, new yamaha cam chain so everything is ready to start. So I tryed firing her up, but after a few kicks nothing, I had the choke pulled so now I tryed to prime her with one full throttle opening. Then bang, she backfired, I was thinking she has to start now, so I kicked again and still she backfired, now my guess was the timing is wrong? Checked, and the timing was good, had the piston on tdc then I noticed the exhaust cam timing is off slighlty (didnt take any pictures sorry) maybe by half a link on the cam chain, tryed adjusting it but theres no chance of aligning the marks on both the intake and exhaust, so fustrating. I took a look behind and the lobs on the intake camshaft arent pointing up, they are more linear (horizontal) to the head, picture no.1 Btw thats my old cam, I installed it becuase it was in mint condition. Picture no.2 is with the intake cam from the new head. So now I know the intake cam is no good, but need to verify which one has sliped the gear on the shaft? Did some rough measurements, so you can see the difference. Any help would be appreciated, thanks.