Yupp.

I have the same drama with mine.

The temps are like the weather, change when they want to.!

Ive given up trying to tune this engine, just let it run rich.

I get smoke coming outta the glow plug hole a lot, I dont bother anymore.

I think its normal, not too sure tho.

Try and keep it running a lil' bit rich, and try keeping the temps inbetween 240 - 260

Would run fine.