First you must break-in your engine. Take a look at that picture first:



You can see 3 needles as you can see at your engine too, right?

The old school method is the following:
With the needles at factory settings, you run your engine for 1 tank with the wheels off the ground at idle speed. The next 5 tanks you are doing them with the wheels on the ground but not overthrottle. Do some 8 figures or loops while at midspeed (half throttle). Then you start leaning (turning right the high speed needle (HSN)) your engine a 1/8 of a turn each time untill you reach the best top speed and best temp. You will see the engine start powering up. Get a temp gun yourself and see the temp each time. The temp MUSTN'T pass 135 deegrees celsious while running your engine.


Take a look at that series of break-in, it might help you: http://www.youtube.com/watch?v=pAggkhHqEkw

The method i gave it's a simple one. Other guys maybe doing something different, or running more tanks, i don't know. That works for me.

The chassis is hitting the ground. It's freakin normal for the buggies while landing from jumps