I actally adjusted the idle, I think. That is if the adle adj. is the large slotted screw mounted on the fuel injector which adjusts the throddle linkage. I run better when warm now but still takes a long time to "warm -up" to idle. If my foot is taken off the pedal when cold the engine stalls immidiatly.

I used the Iso Heet in the red bottle that says its for use in diesel engines
Thanks for the info on the possible filter plug. I'll try that too.