Get it hotter ;-) 120 is barely expanding the internals if at all. I raced motocross for 14+ years before getting into RC, and I beat my friggin head against the wall quite a few times before I got the hang of it. My best advice would be to find someone local who is already into Nitro to help you out at the start. Once you get the engine fired up and broken in....the rest is cake. The break in process is by FAR the worst for a newbie. The engines are hard to start, tight, finicky.....all because they are new.
I'd be happy to hop on the phone with you and see if I can help you out though....
Just remember these tips:
1. Preheat the engine as hot as you can get it....or to @ 200-220.
2. Make sure your glow ignitor is FULLY CHARGED
3. Make sure your engine is primed (Cover the exhaust outlet, spin it over until you see fuel enter the carb)
4. Make sure your engine is NOT flooded. If it is, pull out the glow plug, flip over the car/truck and crank it until all the raw fuel is expelled.
5. Make sure your radio is ALWAYS on before you turn the car on
6. Don't be afraid of the needles. If you raced MX, you understand the difference between rich and lean...use that to your advantage!
7. Take a deep breathe and try again ;-)