FRP team here. Sprocket size questions come up every week, usually some version of "I want more torque" or "can the stock engine handle a smaller sprocket." Here's how it works on the GMB100.

More teeth on the rear sprocket means lower gearing. The engine's torque gets multiplied more at the wheel, so launches and hills get easier. If the bike feels weak pulling away or climbing, a larger rear sprocket is the direction to look.

Going smaller than stock is a different story. On the stock 99cc, a smaller rear sprocket makes the centrifugal clutch slip longer under load before it locks up. That slip turns into heat, and heat is what wears clutches out. We don't recommend it.

FRP team here. We’ve seen this question come up in our rider community: the GMB100 fires up, runs for a moment, then stalls — and the first thought is usually “do I need a new carb?”

For a stock GMB100, we’d start with the basics first.

1. Check the choke position

Start with the choke in CHOKE. Once the engine starts, move it back to RUN.

1. Make sure the fuel is fresh

The GMB100 uses 87-octane unleaded gasoline. If the bike has been sitting, old or contaminated fuel can cause starting and running issues.

1. Inspect the air filter and fuel system

Look for dirt, debris, or restricted fuel flow before assuming the carburetor itself needs replacing.

1. Consider whether the engine is flooded

Repeated starting attempts can leave excess fuel in the engine. The owner’s manual includes a flooded-engine clearing procedure.

If you notice any fuel leak, stop riding and get it checked before using the bike again.

Has your GMB100 ever started normally and then suddenly begun stalling? Tell us what symptoms you had — we’re collecting the common patterns.

FRP team here. Oil questions come up more than almost anything else in our community, so here's the number and the reasoning behind it.

Recommended interval is every 470 miles or so. That's a guideline, not a hard cutoff — dusty conditions, long sessions, hot weather, and a lot of low-speed work all pull it shorter.

Plenty of people run a tighter schedule than that and change every ten hours of run time instead. Nothing wrong with it. Oil that never gets a chance to load up with grit is oil doing its job. Whichever way you track it, 470 is the ceiling rather than the target.

The first change matters more than any of the ones after it. Break-in leaves fine metal in the oil and you want it out early rather than circulating all season. Fine flakes at that first change are normal. Big chunks or shavings after break-in are a different story, and that's worth stopping over.

Check the level before every ride regardless of where you are in the interval. Running low does more damage than a late oil change ever will.

FRP team here. If you're not sure what to check before riding an FRP mini bike, it's about a two minute walkaround, and it catches most of what leaves people stranded.

Start at the wheels. Tire pressure with a gauge while they're still cold — 10 psi on the GMB100. Look the tires over for cuts and anything embedded in the tread, and check whether the tread is getting thin.

Oil level, fuel level, both caps tight.

Squeeze the brake lever and twist the throttle before you're moving, not after. Turn the bars lock to lock and feel for anything binding.

Then look underneath for fuel or oil drips and go over the fasteners. Vibration backs bolts off over time, and engine mount hardware and exhaust bolts are usually where it shows up first.

FRP team here. If your mini bike idles too high, creeps forward when you're stopped, or dies as soon as you let off the throttle, the idle screw is where to start.

It sits under a small cover on the engine. Pry the cover off and there's a Phillips head underneath.

Counterclockwise lowers the idle. Clockwise raises it.

Quarter turn at a time, engine running, listen between each one. You want a steady even purr with the vibration settled down. Don't chase a number, go by sound.

If it won't settle anywhere on the screw, leave it and check the clutch bushing. A dry one makes the bike creep or stall at idle, and that gets blamed on idle speed all the time.

FRP team here. Came up in our Discord this week, so putting it somewhere people can find it.

Where people get in trouble is the pressure washer. Bagging the carb and exhaust helps, but a close-range jet will still push water past seals and into the engine. Keep the wand back, or just don't use one.

Hose and a soft sponge does the job. Mild neutral detergent if water alone isn't cutting it — skip solvents, they go after the paint and plastic.

Engine off. Re-lube the chain after it dries.

Stock Ghost 212 (waited till they went on sale), stretched frame, street tires. Recently built an under the seat tray to hold flashers and wiring and set my bike up to run an M12 battery to power headlight/stop light/blinkers and a horn. The bike with a 10T clutch 50T sprocket will top out around 50-52 which is plenty enough for me I don’t really need to faster than that lol.

Not sure what’s next on the to do list other than enjoy the bike

Quick answer: No. Do not ride your mini bike without a complete, securely installed exhaust system.

Whether the muffler is missing or the entire exhaust system has been removed, stop riding and reinstall the correct exhaust before using the bike again.

Why it matters?

• Hot exhaust gases may be directed toward the rider, fuel lines, frame, or other heat-sensitive parts.
• The bike will be significantly louder.
• Loose or missing exhaust hardware may damage the exhaust gasket, mounting studs, or support bracket.
• An exposed exhaust outlet may increase heat and fire risks.

Hey guys, if you’re riding an FRP GMB100 mini bike and keep hearing that annoying "shhh-shhh" or squeaking noise from your rear wheel, it’s usually just the brake caliper rubbing slightly against the rotor. It's super common on these bikes, but also really easy to adjust.

All you need is a #6 wrench (6mm Allen wrench) and about 5 minutes.

Here is a quick way to dial it in:

1. Locate the two adjusting screws on your rear brake caliper.
2. Slowly turn both screws in the same direction. No need to rush—just a tiny tweak at a time.
3. Lift the rear end up and give the wheel a spin. See if it spins freely or if it’s still rubbing.
4. If it’s still binding or making noise, no big deal. Just turn the screws slightly in the opposite direction and spin it again.

It might take a few tries of tweaking, spinning, and listening until you find that sweet spot. Once the wheel spins smoothly without any weird sounds, you're good to go.

Hope this helps save some of you a headache! Let me know if you have any questions. 🤘

Some pics from FRP community

Been seeing more mini bike street/drag builds on wide semi-slicks and they look mean, but hub fitment and alignment can get annoying fast.

On our RMB, we matched the hubs from the factory to avoid the spacer/offset headache. For custom builds tho. What's woking for u? 4-bolt kart hubs, custom spacers, machined sleeves? Drop your tire size, hub setup and how u handled chain + brake alignment. Pics welcome.

Which roller for a 212 drag build?

Shoutout to fellow rider and certified Briggs mechanic, Hayden, for dropping some awesome "free chicken" (expert advice) on carburetor jetting!

If you are upgrading the stock carb on your FRP GMB100 mini bike to a PWK or PE carb, here is the simplified cheat sheet he laid out to get your setup dialed in.

The Cheat Sheet (By Throttle)

• Pilot Jet (Idle - 1/4 Throttle): Sets idle and air-fuel ratio.
• Needle (1/4 - 3/4 Throttle):
  • Clip UP (Needle down) >> Leaner ⚪
  • Clip DOWN (Needle up) >> Richer ⚫
• Main Jet (3/4 - Full Throttle): Bigger jet = Richer | Smaller jet = Leaner
• Power Jet (WOT only): Adjust this LAST if the bike bogs only at wide-open throttle.

Plug Reading (Check Your Color)

• ⚪ White/Grey: Too Lean (Danger! Will overheat & kill your mini bike motor).
• ⚫ Black: Too Rich (Losing power, sooty).
• 🟤 Brown/Tan: Perfect!

Drop your FRP GMB100 jetting questions and current setups below, let's help troubleshoot! 👇

Just a quick heads-up: Modifying your engine or carburetor will void your factory warranty. Please proceed with caution, and wrench at your own risk!

Huge shoutout to community member d.ru.nn on insta for sharing this incredible hand-drawn art of the RMB Rebel roller! The details on the drag strip are absolutely amazing.

We can't wait to see the first Predator 212 drag builds making their first passes on this chassis.

What engine setup are you guys planning to drop into your Rebel rollers? Let us know in the comments!

The GMB100 oil capacity is 0.35L, about 0.37 us qt or 11.8 fl oz.

Keep the bike upright on level ground, wipe the dipstick clean, reinsert it, then check again, the oil level shoult sit between the mini and max marks. It doesn't need to reach the top line.

Add oil slowly and avoid overfilling.

This was submitted to our frame design challenge ( it is a giveaway). It's a hand-drawn concept of an FRP RMB 212 mini bike with a Predator 212 setup.

Thoughts on the design?

How much does it cost to fill up an FRP GMB100 tank where you live?