El, the ttr is cold-blooded. She's definitely worse if not ridden for a while. I've never bothered stuffing with the jetting though (do a search on the mini forum for a few tips about it). The other thing you should do is, either find out how to put a chain back on the sprocket or b) get a decent chain guide (BBR make them).
I unload my bike & start her up, then eventually think about getting ready to go riding. Oh, the other thing I've found is if I've forgotten to turn the gas on, or the choke on, she just doesn't want to play (the kdx I can get away with forgetting the gas for a few minutes & the choke is more a token gesture).
I've also found spare levers is a good thing. Oh the one thing that really pisses me off about the ttr is the gear shifter - it's like putty. I dropped it once & now often have to bend it back out. It's a fun bike but there are some niggly things that drive me nuts about it.
The stock chain doesn't last overly long before it starts jumping off the sprocket (I had a demo bike for a couple of weeks and first encountered chains off the sprocket - I've now learnt to check the chain often, but even more importantly, how to fix it). It's the rear sprocket and is not a biggie, but if you have a half-way decent look at the chain guide (compared to others) you'll see why.
I can't think of anything else (the heat-shield missing from mine is due to a run-in with something rather than a design fault - coming ex somewhere), the spark plug lasted around a year putting behind kids, the gas tank may as well be disconnected, it just doesn't use any, the air filter doesn't require much looking at, let alone cleaning, the oil, well, it's a low stress engine ;)
Enjoy your new toy and don't cry too hard when you do leave the first character marks, it's part of it :)
Have fun