Often, it can be hard to determine exactly what carburetor adjustments need to be made. And since practice time is limited, you don't have time to be making a bunch of different changes. When you're trying to determine the best change to make, Dorton suggests going ahead and making your changes in big steps. This way your driver should be able to tell you exactly what the change did to performance. Either it helped performance or it hurt it. You may have to go back and tone down the adjustment a bit, but at least you won't be wasting time with tuning changes that are too small to really let you know which way you need to go.

After Practice
After practice is complete, Dorton recommends performing another visual inspection. Again, you're checking the belts for wear, oil and coolant leaks, burned plug wires, and anything else that might be amiss. Dorton also makes it a habit to talk to the driver just to get his opinion on the state of the engine. Ask him or her how the engine responded to throttle inputs, if everything sounded OK, and if he noticed any vibrations. He or she should also be able to tell you how hot the oil and water temps got during the run.

"The absolute last thing I want to do between practice and the start of the race," Dorton adds, "is have to change the plugs. You want to avoid installing any new plugs at all costs right before a race, because you just don't know if you are going to get a bad plug. You won't discover it until the race starts, and then it's too late. I encourage teams to keep a set of plugs on hand that they ran some laps on during a test session. That way, you know they're all good."

If you get water or oil temps that are higher than usual, and the cooling system seems to be in working order, you should check to make sure the engine isn't going lean. Often, this isn't a jetting problem, but a problem with fuel delivery instead. Check that the fuel filter isn't clogged, there are no leaks in the fuel lines, the fuel pump is working properly, and the pickup in the fuel cell hasn't moved.