The main thing you need to concern yourself with is engine temperature, you didnt say what type of engine you have so this is a general answer. Your engine should never run over 300 degress ever, try to keep the temps between 200 and 250 anything hotter will shorten the life of your engine. Go out to the hobby store and invest in some type of temp gun or on board temp guage to monitor the temps. When you run your engine near full throttle most of the time it will run hotter so in that case you will want to richen up the top end mixture a little more than if you run at moderated speed, in that case you could lean down the top end a little. Run you car at full throttle for a few minutes and check the temp, if its high righen it up. In time you will get the hang of it but heat is the killer. also be sure to oil your air filter with special air filter oil, if its a 2 stage filter only oil the main filter not the pre filter. Be careful not to allow dirt to fall into the engine when removing the glow plug, hold the car upside down and wipe the area with a q-tip to keep out the dirt. Minute particules of dirt can scar the sleeve and cause permanent damage to the piston and sleeve. Hope this helped you out.