If you are looking to get more power out of your mini bike or go-kart, you have probably seen performance kits categorized by "Stages." But what do these numbers actually mean, and which one is right for your specific build?
To clear up the confusion, GPS Racing Engine Builder Paul Crafton breaks down exactly what parts and performance gains you can expect from a Stage 1 kit all the way up to a fully built Stage 5 racing
A Stage 1 kit is your first step into aftermarket performance. It takes a stock utility engine and opens it up to breathe like a true powersports engine.
What it includes: An upgraded air filter and a less restrictive exhaust.
The Result: By allowing more air in and more air out, you get a noticeable boost in power and throttle response without having to open up the engine block.
Stage 2 gives you a slight performance bump, but its primary focus is on internal safety and durability so your engine can handle higher RPMs.
What it includes: A billet aluminum flywheel and a billet connecting rod.
The Result: The stock cast parts inside your engine can fail under heavy stress. Upgrading to billet components ensures your engine holds together when you decide to push it harder.
This is where you start making significant internal modifications to aggressively increase your horsepower and speed.
What it includes: A hopped-up camshaft, a high-flow Shredder cylinder head with bigger valves, and a larger 26mm slide carburetor.
The Result: Drastically increased fuel delivery and airflow, resulting in a fast, aggressive engine for serious riders.
Stage 4 is not designed for a standard neighborhood yard kart. This is a dedicated racing engine built to scream at high RPMs.
What it includes: A massive camshaft, heavy-duty dual valve springs, high-compression internals, advanced ignition timing, and a large racing carburetor.
The Result: An engine capable of safely turning 9,000 to 10,000 RPMs. It requires regular maintenance and is meant for the track or serious competition.
When you just want to go as fast as possible, you step up to Stage 5. This is an off-the-shelf, fully equipped racing motor.
What it includes: All the high-end internal racing components of a Stage 4, but specifically tuned and built to run on methanol fuel instead of standard gas.
The Result: Maximum off-the-shelf horsepower turning at roughly 10,000 RPMs. Because it runs on methanol and uses extremely stiff valve springs, it requires the highest level of strict, routine maintenance.
Whether you want a simple Stage 1 cruiser or a Stage 5 drag racing monster, we have the exact parts you need to hit your horsepower goals.