Re: What are some of your other hobbies?
Those little engines are screamers & are very sensitive to changes in the weather (temp & humidity)
Do you have a temp gun?
The way I tune my engine is by checking the temps, find out what the temp is when it's running it's best then you always have a starting point for tuning, too cold lean it out a bit, too hot richen it up a bit.
Also find a glo plug you like & stick with it, that'll be one less variable to deal with.
Being a watch guy this will make sense to you, think of the mixture needle as the hour hand on a watch, there is 12 hours on the watch & you don't want to move the needle more than 1 hour at a time when tuning it, that way you never get too lost in your settings.
Glad you like the radio, they are a big improvement over the stockers.