This is just me, but I would put a new glow plug in it, too. And with any fuel mixture issue, I make sure the carb and fuel are absolutely clean. It's sort of like re-booting Windows-sometimes you really have to, and at worst, it doesn't hurt. Then ever so slowly lean the idle needle (a tiny bit at a time!) until you get a good idle and transition. Sounds right, though-bottom end is too rich and it's loading up with fuel at idle.