Why Remove the Governor
The factory governor on a Predator 79cc exists to hold the engine at a steady, predictable RPM regardless of load — exactly what you want on a generator or pressure washer, and exactly what caps your power on a go-kart or mini bike. It does this by watching engine speed internally and pulling the throttle plate back the moment you approach the RPM it was tuned for at the factory.
Removing the governor doesn't add horsepower by itself — it simply lets the engine reach the RPM its valve train and port timing were already capable of. On a stock 79cc, that alone commonly takes the engine from a governed ~3,600 RPM to over 5,000 RPM, before you've changed a single other part.
The governed RPM on a general-purpose engine like this is tuned for stationary equipment, not karts or mini bikes. Removing it isn't defeating a safety feature so much as recalibrating the engine for a different job — but it does mean RPM control becomes your responsibility instead of the factory's. Keep that in mind as you read through the safety section further down.
How the 79cc Governor Works
The 79cc uses a mechanical governor split across two locations. Outside the engine, your throttle cable pulls a return spring connected to a metal pivot arm that passes through the crankcase wall. Inside the engine, that arm is linked to a small plastic gear meshed with the camshaft gear. As RPM climbs, the spinning gear pushes the arm outward, which pulls the carb's throttle plate closed — fighting your throttle input no matter how far you've opened it.
| COMPONENT | LOCATION | ROLE |
|---|---|---|
| Throttle Rod & Return Spring | External, top of engine | Links throttle cable input to the pivot arm |
| Metal Pivot Arm | Passes through the crankcase wall | Transfers gear movement to the carb throttle plate |
| Plastic Governor Gear | Internal, meshed with the cam gear | Spins with engine RPM, pushes the arm as speed rises |
| Retaining Pin | Behind the flywheel | Holds the governor gear onto its shaft |
| Small Washer | Between the gear and case wall | Keeps the gear seated — easy to lose once it's out |
Layout can vary slightly across production runs. Confirm what you're looking at against your own engine before removing anything.
Removal Methods at a Glance
| METHOD | RPM CEILING | REVERSIBLE | STATUS |
|---|---|---|---|
| External Bypass Only (stiff wire/spring) | Modest increase; gear still spins past its design speed | Yes, easy | GEAR AT RISK |
| Full Internal Gear Removal | 5,000+ RPM | No | RECOMMENDED |
| Full Removal + Billet Flywheel & Springs | 5,500+ RPM (build-dependent) | No | BUILT FOR IT |
RPM ceilings assume no other supporting mods beyond what's listed. Actual results depend on valve springs, carburetion, and exhaust — verify with a tachometer rather than trusting any number you read online, including these.
Choosing Your Path
Tools & Materials Needed
Save the retaining pin and small washer behind the governor gear — they're easy to lose inside the case and effectively impossible to fish out once the cover's back on.
Step-by-Step Removal
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01
Pull the spark plug wire and drain the oil into a pan before doing anything else.
-
02
Remove the six side cover bolts and pull the cover off slowly. Save the gasket if the engine is new or low-hours.
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03
If the camshaft comes out with the cover, don't worry — the lifters may come with it. Everything goes back exactly where it came from; just note their orientation before setting them aside.
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04
With the cover off, you'll see the camshaft, the crankshaft in the center, and the plastic governor gear meshed with the cam gear off to one side.
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05
Unhook the throttle rod and governor spring from the top of the engine.
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06
Follow the pivot arm down into the block and remove it. Rotating the crankshaft by hand often gives you the clearance needed to pull it free.
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07
If it won't clear, cut the top of the arm off with a Dremel and lower the remaining piece out through the block.
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08
Plug the hole the arm left behind with a tapped 1/4-20 bolt so you don't end up with an oil leak.
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09
Remove the blower housing, then the flywheel nut — an impact wrench makes short work of this.
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10
If the flywheel won't lift off its taper, thread the nut back on a few turns and give it a sharp hammer tap. Avoid damaging the crankshaft threads.
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11
With the flywheel off, you'll see the pin holding the plastic governor gear in place. Tap it out — the pin and gear will drop down into the case.
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12
Fish out the gear, the pin, and the small washer behind the gear. Double and triple check nothing is left loose inside before moving on.
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13
Plug this second hole the same way as the first, with a tapped bolt that won't work loose or fall into the case.
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14
Reinstall the cam if it came out, lining up the small timing dimples on the cam gear and crank gear.
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15
Reinstall the side cover with a new gasket, then the flywheel, fan, starter cup, and blower housing.
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16
Set up a direct throttle cable and return spring straight to the carb's throttle arm — there's no governor left to work against it.
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17
Check valve lash, refill the oil to the correct level, and reconnect the spark plug.
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18
Start the engine and let it idle before touching the throttle. Confirm smooth response with no surging, then check both plugged holes and the side cover for leaks.
Take photos before you disconnect anything, and use a magnetic parts tray to keep every fastener and small part sorted by step. On an engine this small, a dropped washer is a lot easier to lose than to find again.
Safety & Rev Management
Once the governor is gone, nothing inside the engine stops you from over-revving it — that job now belongs to you and whatever supporting parts you've installed. Treat rev management as part of the mod itself, not an afterthought for later.
The stock valve springs are doing you a favor here: once RPM climbs high enough, they'll float and cap your power before anything breaks. That's a rough built-in ceiling, not a tuned one. If you upgrade to stiffer springs to chase more RPM, that cushion goes away — get a tachometer in the loop before you do.
Builders chasing more RPM after governor removal commonly start around 18 lb valve springs, but treat that as a starting point to match against your camshaft and target RPM, not a fixed spec.
A de-governed engine is intended for karts, mini bikes, and off-road builds used off public roads. Check your local laws before running one on anything street legal, and always wear appropriate protective gear when operating a modified engine.
79cc-Specific Notes
Frequently Asked Questions
Related Calculators & Guides
🔧 Build Guide
⚙️ Related Upgrades
🧮 Useful Calculators
🏁 Other Predator Engines
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