As much as I wanted to believe in these mills, I'm not convinced anymore. The carbs are absolute junk, as I've replaced the o-rings many times only to have them fall apart again and again. Put a V-spec carb on it, it will tune normal and run normal, and you won't have to replace o-rings every few tanks. This is only MY opinion and not meant to piss anyone off, cuz that's not why I'm here. I was just as fustrated with these motors and probably blew $300 in glow plugs to get it to stay running.