The Diamondback starts off with a 22R engine.
See Initial Repairs
The 22R can run with low, or no oil. If the oil is low, the moving parts will wear much faster.
A hot engine will generate less horsepower, as well as degrade the quality of its parts at a much faster rate.
Check Engine Light
See Engine Diagnosis
An exhaust header can be bought at the Auto Parts Store, and will give a nominal +10hp increase.
An EFI conversion can be bought from the Auto Parts Store. This consists of an EFI intake, throttle body, and cone filter. This will give a nominal horsepower and fuel economy boost.
After an EFI conversion, the cone filter should be removed and replaced with a Turbo Inlet Pipe. The exhaust header must be replaced with a turbo exhaust. A turbocharger needs to be bolted to the turbo exhaust, which connects to the turbocharger. The same cone filter can be placed directly onto the turbocharger.