Mmmm did you replace the regulator too? Does your quad have that ground put safely sustem in the trottle leaver body? If that ground wire is disconnected somehow under the gas tank left hand side or at the battery ground wire, your quad will not fire. I just had that w weeks ago. The tiny black ground wire at the battery was loose. Ran like crap. This timy ground wire runs the throttle safety system. Check all those connections to the Carborator etc. If you quad haa that system. I hate that sustem om them but mine has it. I jave not tried to remove that system from the quad. Hope that helps. Sorry for the late reply.
whats a race cut harness? many yfz owners seem to be going through this haha I just replaced my stator and rectifier and no spark! fired up fine before
No power loss, it would either fire or not fire at all. Eventually it just would not fire at all. Power loss is related to timing or the low premium regular gas you use or your carb. But I have found that you do need to run high octane gas on these, it will run cooler too. I found my 450 sputter at high rpm if you use low octane gas. Always use high octane gas
You can just tip the bike on the side and not drain the oil but I had actually just changed the oil before thus happened and found the oil pretty dirty from the stator getting ground up so had to replace the oil anyway. So went ahead snd tipped it on all 4 wheels and let the oil gush out the side with the side cover off. Most of the grime came out by doing thar. I put in new oil and filter too and good to go