First time posting, my son bought a 400EX with a 440 kit and a Keihin carb and after riding it a couple years it sat in his mom’s garage for several years. He asked me if I could revive it and I thought, how hard could it be? I have been unable to find any numbers on it to identify its year of manufacture. I pulled the head and and had a fresh valve job done but after reassembling it I cannot get it to run. I’ve tried setting the timing several times to no avail. In hind sight I’m now wondering if, and I didn’t at the time, I should have made note of it;s timing marks. So my question is, it has an aftermarket cam (Hot Cams) with an inscription between lobes "EHR 8" . would i be using the factory timing set up or would anyone know if this cam requires advancement?