Mini Motorcycle and Moped Keys: Grom, Monkey, Ruckus

Quick answerA lost key on a mini motorcycle is usually one of the simpler key jobs. The Honda Grom, Monkey, Navi and Ruckus use a plain cut key with no chip, so a replacement is cut to the key number or to the bike's own locks and tested in the ignition, seat and fuel cap. The catch is that these bikes are bought used, shared and stored casually, so the spare key and the key number tag are missing far more often than on larger bikes.

Small bike, simple key

Honda's small bikes are a good guide to the whole class. The Ruckus, Metropolitan, Navi, Monkey and Grom all use a mechanical cut key, with no transponder for an immobilizer to check. Honda's Grom owner's manual has a section on the ignition key and key number and no immobilizer section at all. That means there is no programming step and no dealer software: a correctly cut key is a working key.

The same key does more than start the bike. On the Grom, the manual shows the ignition key locking the steering at the ignition switch, opening the fuel fill cap under its lock cover, and releasing the seat through a seat lock. When the key goes, you lose all of those at once.

Bike	Key type	Chip
Honda Grom	Plain cut key for the ignition and steering lock, seat lock and fuel fill cap	No
Honda Monkey, Navi, Ruckus and Metropolitan	Plain cut key	No
Honda CRF50F and similar minis	Simple two position key switch for the ignition only	No

The key number and where Honda expects you to keep it

Honda supplies a key number plate with the keys. The Grom manual tells owners to record the key number, to store the spare key and the number in a safe location, and to take the spare key or the key number to a dealer to have a duplicate made.

It also says what happens when neither exists: if you lose all ignition keys and the key number, the ignition switch assembly will probably have to be removed by the dealer to determine the key number. That is the dealer route, and it means getting a bike that cannot be started to the shop. The mobile route is the same idea done where the bike sits: the key is worked out from the bike's own lock, cut, and tried in every lock before the job is finished.

Kawasaki handles key numbers the same way on its bikes. Its manuals describe a key number supplied with the key, sometimes stamped on a separate plate, and tell owners who cannot find it to contact the selling dealer.

Why the spare is so often gone

Mini bikes change hands a lot. They are first bikes, pit bikes, campus transport and project bikes, and they are commonly sold person to person with one key and no paperwork folder. The key number plate is small and looks like packaging, so it is thrown away or left on a ring that is later lost. By the third owner there is usually a single worn key.

That single key is a risk on a bike this easy to move. If you have just bought a Grom, Monkey, Navi, Ruckus or Z125 with one key, the cheapest moment to fix it is now: a duplicate cut from a working key is quick, and you can record the cuts for the future. Waiting until the last key is lost turns it into an all keys lost visit.

If you do not know who else holds a key to a bike you bought used, a copy is not the answer. Having the locks rekeyed means old keys stop working.

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Keys locked under the seat, and other small bike problems

Honda's Grom manual carries a specific warning: the seat locks automatically when closed, so take care not to lock your ignition key under the seat. It happens exactly as the manual fears. The key is used to open the seat, set down in the tray, and the seat is pushed shut.

Other common calls are a key bent in a pocket or snapped in a tip-over, and an ignition that has been forced. Small bikes are frequent theft targets, and a damaged ignition switch has to be repaired or replaced before a key means anything. Honda's manual also notes that a metal key holder can damage the area around the ignition switch, which is a fair reason to keep the ring light.

Mopeds and 50cc machines

Modern 50cc scooters such as the Ruckus, Metropolitan, Yamaha Zuma 50 and Genuine Buddy 50 are covered in our scooter guide, because their ignitions also release the seat and may sit behind a key shutter. Honda's little trail bikes, such as the CRF50F, have a basic OFF and ON key switch that Honda says is there to prevent unauthorized use.

Older pedal mopeds are a mixed bag, and we would rather see the bike than guess. Tell us the make and send a photo of whatever lock it has, whether that is an ignition switch, a steering lock or a fuel cap. Proof of ownership still applies. If a small bike came with a bill of sale and nothing else, read our guide on proof of ownership before you call.

Make, model and year, and a photo of the ignition
Any key you still have, including a broken one
The key number, if it is on a plate, in the manual or in the sale paperwork
Photo ID and registration or title
Whether the ignition or steering lock shows damage

Quick questions

Does the Honda Grom have a chip key?

No. The Grom uses a plain cut key, and Honda's owner's manual describes only an ignition key and key number, with no immobilizer section. A correctly cut key needs no programming.

I bought a Grom with one key and no key number. What should I do?

Have a duplicate made from the working key now. Honda's manual says that with no keys and no number, the dealer would probably have to remove the ignition switch to find the key number, which is far more trouble than a copy.

Can a key be made for a Ruckus or Navi with no key at all?

Yes. They use plain mechanical keys, so a new one can be cut to the bike's existing lock once photo ID and proof of ownership have been checked.

I locked my Grom key under the seat. Is the lock ruined?

No. The seat lock can be opened without damage and you get your key back. Honda's manual warns about this exact mistake because the seat locks automatically when closed.

Services that can help

Key details by make

Keep reading

Scooter Key Replacement: Shutters, Seat Locks and ChipsYes, a key can be made for almost any scooter, and on most 50cc to 150cc models it is a plain metal key with no chip.
When to Get a Spare Motorcycle Key, and Why NowGet a spare motorcycle key as soon as you are down to one working key.
Bought a Used Motorcycle With No Key? Here's What to DoA used or auction motorcycle without keys can usually get new ones, but plan on the full all-keys-lost process and bring the signed title or other transfer paperwork plus photo ID, since a locksmith or dealer has to tie you to the VIN.
How to Find Your Motorcycle Key CodeA motorcycle key code is a short number or letter-number code that tells a locksmith or dealer how to cut a key for your locks.
Vintage and Classic Motorcycle Keys: Codes, Blanks, WearA key can usually be made for a vintage motorcycle even when no original survives, because these are plain mechanical locks with no chip.

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Page last updated November 14, 2026.