New engine - not as easy as it looks !!!!

[andys]

Started breaking in my new engine. All went well, did it as per engine instructions, although I heated it up first with a heatgun. Then ran it a little and started leaning it out as the factory setting were very rich.

A few days passed, went to run it again today (couldn't pre heat it this time) and it just kept cutting out on the box when I gave it the gas. In the end I went back to stock settings, got it warmed up and started the leaning process again.

What did I do wrong, is it just the cold weather and a new engine ?

Engine is a Tecnopower and pipe combo. Went like stink when I got it running again.

Very tempted to get a Surestart engine pre heater now....