KTM 640 LC4 and 625 SMC Key Replacement

Quick answerKTM's LC4 singles are plain-key bikes with no immobilizer. The 640 LC4 Enduro and Supermoto manuals describe an ignition lock that also blocks the handlebar and a locking filler cap on the same key. The 625 SMC and SXC are barer still: an ignition lock, a separate handlebar lock on the steering head and a fuel cap that simply unscrews.

KTM 640 LC4 and 625 SMC key quick facts

KTM's owner's manuals for the 640 LC4 Supermoto (2003), 640 LC4 Enduro (2006) and 625 SMC (2005) each provide a box to record the key number.
On the 640 LC4 the ignition key withdraws in two positions: ignition off, and ignition off with the handlebar blocked.
The 640 LC4 filler cap locks: insert the ignition key, turn 90 degrees counterclockwise and lift the cap off.
The 625 SMC and SXC manual describes a handlebar lock on the control head that is separate from the ignition lock.
On the 625 SMC and SXC the filler cap has no lock and is unscrewed by hand.
None of these manuals has an immobilizer section.

KTM 640 LC4 and 625 SMC key types by year

Years	Models	Key type	Chip	Notes
2003-2006	640 LC4 Enduro, 640 LC4 Supermoto	mechanical cut key	no	One key for the ignition lock with handlebar block and for the locking filler cap, per the 2003 Supermoto and 2006 Enduro manuals. For other years, tell us the year and we confirm.
2005	625 SMC, 625 SXC	mechanical cut key	no	Ignition lock with three switch positions plus a separate handlebar lock. Screw-on fuel cap with no lock. From the 2005 manual; for other years, tell us the year and we confirm.

Two different lock layouts in one engine family

The 640 LC4 models were KTM's road-going singles, and they have a road bike's ignition lock. Its three positions are off, on and off with the handlebar blocked. To block the bars you press the key firmly into the lock, turn the handlebar to the left and turn the key to the left. The key comes out there and in the plain off position.

The 625 SMC and its enduro sibling the SXC are closer to competition bikes. Their ignition lock offers ignition off, ignition on with lights off and ignition on with lights on. Steering security is a separate lock on the control head: turn the handlebar fully to the right, insert the key, turn it left, press it in, turn it right and withdraw it.

Need a key for your 640 LC4 Enduro?

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The warning KTM prints about the handlebar lock

The 625 manual is blunt about one habit. Never leave the key in the handlebar lock, because if the steering is turned to the left the key could get damaged. The result can be a blade bent or sheared off in the lock on the steering head. If that has happened to your bike, leave the stub alone and call. A broken piece that has not been pushed deeper is much easier to remove.

Fuel cap and seat

So on a 640 the things a lost key keeps you from are starting the bike, unlocking the bars and refueling. On a 625 it is starting the bike and, if the bars were locked, steering it.

640 LC4 Enduro and Supermoto: locking filler cap worked by the ignition key, 90 degrees counterclockwise to release and 90 degrees clockwise to lock
625 SMC and SXC: plain threaded filler cap, counterclockwise to open
640 LC4 Enduro seat: lifted at the rear and unhooked from an oval-head screw, with no key lock described
625 SXC seat: the manual describes removing it without tools

Lost key service for an LC4

We check photo ID and the registration or title, then make a key from the ignition lock, or from the key number if the first owner wrote it in the manual. On a 640 the new key is tried in the ignition, the handlebar block position and the filler cap. On a 625 we check the ignition lock and the handlebar lock.

A used LC4 often arrives with a single worn key. KTM's manuals recommend treating the ignition lock with contact spray as part of regular care, and a lock that has had none in twenty years may need cleaning before a fresh key feels right.

Where to find the key code

KTM's LC4 manuals ask the owner to enter the chassis, engine and key numbers on the first page. If that box was filled in, the key can be cut to the number. If it is blank, the key is made from the locks on the bike.

What to have ready

Have this ready when you call or text

Year, make and model of the bike
Where the bike is parked
Whether you have any working key, a broken key or a key code
Photo ID and registration or title (we verify ownership before making a key)

KTM 640 LC4 and 625 SMC key FAQ

Does a KTM 640 LC4 have a chip key?

No. KTM's manuals for the 640 LC4 Enduro and Supermoto describe an ordinary ignition key with a key number and have no immobilizer section.

Why does my 625 SMC have a second lock on the steering head?

That is the handlebar lock. On the 625 SMC and SXC the ignition lock does not block the steering, so KTM fitted a separate lock on the control head.

Can I refuel my 640 LC4 without the key?

Not with the original cap. The 640 LC4 filler cap locks with the ignition key, so a lost key also means a locked tank until a new key is made.

The key broke off in my 625 handlebar lock. Is the lock ruined?

Usually not. The broken piece can normally be extracted and a new key cut. KTM's manual warns that a key left in that lock can be damaged when the steering is turned.

More KTM models

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Broken Motorcycle Key in the Ignition: What to DoIf your key snaps in the motorcycle ignition, stop, keep both pieces, and do not try to turn the cylinder with the stub or dig the fragment out with a knife or screwdriver.
Motorcycle Key and Lock Care: What Makers RecommendKeep water and grit out of the locks, use a small amount of a dry or lock-specific lubricant instead of oil, and replace a worn key before it fails.

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Page last updated November 14, 2026.