The problem is that the camshaft sprockets were not put back on correctly. Take them both off, and inspect them for damage caused by not putting them on correctly. If you got lucky, carefully put them back on and make sure the "key" is properly in the grove before tightening them. It is ok to lubricate the shaft and key if this is needed before re-installing the sprockets. Torque them properly, and say "thank you"
Keith
