YUKA mini: false 'front wheel lifted' and tilt warnings, usually a sticking front wheel

What owners report

• A YUKA mini Vision 700 kept triggering its tilt sensor on bumpy grass after some firmware updates in the spring, saying it was tilted or stuck when it was not. Sometimes it beeped and carried on; sometimes it needed someone to restart it. Its owner first found the wheels spun freely, then, pushing them up and down, found they were "definitely sticky" vertically. Cleaning and lubricating cut the warnings but did not stop them¹. Two other owners in that thread say YUKA front wheels trigger lift errors all the time and need constant cleaning and grease¹.
• A mower on a flat lawn stops five or six times a session saying it is tilted, and its owner has to go out, press Grass and Start, and lift it up and down². Two owners reply that theirs does the same, one since the August update, which the September update did not fix². Another owner suggested raising the mowing deck, saying it looked like it was bottoming out. The asker had it on the lowest setting, raised it, and wrote back that this "completely fixed the problem"². That is one owner's result.
• A YUKA mini 500 began tripping over itself as it turned round, with the front casters not turning fully³.
• A YUKA mini 600 keeps stopping across the yard since the last update with no stuck notification, even while backing into the charger; two other owners in the thread say the same, one adding that the wheels also spin⁸. A Mammotion account asked the owner to clear grass, mud and debris from around the front wheels first, and, if it continued, to send photos of how the mower is stuck, the device number and the device logs⁹.
• A YUKA mini 800 on damaged ground gets many messages that the front wheel has lifted, and its owner asked for a setting to turn the detection off⁴. There is no such setting in these threads.

Why a sticking wheel reads as lifted

One owner explains that there is a magnet and a sensor on top of each front wheel. When the wheel sticks as it drops back down, the mower reads it as lifted. Cleaning the wheels and spraying them cured theirs³. Owners also suggest greasing the axle and the pivot stem, and pulling the wheels out to clean and oil them³. In the November thread several owners said the same: cleaning and lubricating where the front wheels move in and out of the body stopped their emergency stops, which they put down to the wheels sticking¹¹. One owner in that thread said new wheels bought from support lasted a month before the stops came back, even with the post lubricated; that is a single report.

What Mammotion says

In July, a Mammotion account told the Vision 700 owner that its team is aware of the issue and is looking for a better solution. It suggested cleaning out the clippings where the front wheel meets the chassis and spraying a little WD-40, and asked owners whose warnings continue to send their device name, order number and a photo of the front wheel¹. On Facebook, Mammotion accounts asked owners to pull each front wheel by hand to feel for stiffness, to follow its front-wheel cleaning video twice³, and to take the wheel out and check that the spring is inside⁴. In November an owner whose mower kept ending in "Emergency stop activated" got a Mammotion reply that the mower stops when it detects an abnormal tilt, and that stiff front wheels, clippings and dust make that more likely. It asked the owner to take the front wheel assembly off and check that a spring is inside, and recommended lubricating the front wheel axle with WD-40 regularly¹⁰.

When cleaning is not enough

One YUKA mini 500 owner messaged support and had two new front wheels, with springs, and a tube of lubricant within a few days, with no problems since³. If yours still warns after a clean, ask support for the same, with a photo of the wheel.

Older units may have no springs at all. A YUKA owner says support asked them to check the wheels were not stuck or dry and whether there were springs under the two front wheels once they were taken apart; there were none, and support was to send some⁵. They suppose some units shipped without front springs, or that the springs came later as a fix; that is their guess. Another owner's replacement front wheels arrived with two springs and two shim washers that were not on the original wheels, and the installation leaflet did not mention them⁶. A Mammotion staff account replied that the new front wheel assembly has changes from the old one and pointed to an installation diagram; the owner replied that the diagram differed from the sticker on the box and asked for a copy to be included in the parcel⁷.

If your mower stops as "trapped" rather than lifted, on open ground, see error 1201 on open ground.