If you ask me, the biggest contributor in failure to complete the U-turn (or figure 8, or S bend, or whatever low speed maneuver your testing authority makes you do) is not technical or mechanical, but rather anxiety. In hyperfixating on not hitting the boundaries, i.e. the sides of the road or the stripes, you often induce underconfidence in yourself which will cause you to hesitate and fail to commit to the maneuver. And the thing about low speed turns on two wheels is that you must commit to the maneuver, because if you slow or stop suddenly you will fall down, or at least go tipsy enough that you won’t be able to resist putting a foot on the ground.

I am not going to offer any advice on technique because others have covered that already (drag the rear brake, etc.). Instead try this:

Go to a big parking lot with absolutely no obstacles or barriers or anything around you. Balance your GoPro or phone camera on something so you can record yourself. Ride out and back, and do the absolute tightest U-turn you can manage. Don’t think. Don’t look at the ground. Don’t hesitate. Just do it.

Review your footage. Go back out and chalk where your tires went. Measure the distance. Compare it to a road. I’ll bet you a penny or whatever your local currency is that without the added pressure of worrying about barriers, your turn was small enough to fit into two traffic lanes, exactly as required.

All that said, I don’t understand the obsession testing authorities have with forcing people to do twiddly little U-turns and loops and circles at parade speed. None of that shit will successfully teach you how to ride a motorcycle down the road. It’s pointless frippery for the sake of criticizing people over something that’s truly meaningless in almost all situations. Once you get your license, if you have to get your bike out of a tight parking spot and that requires doing a three point turn and putting your foot down in the middle, is an instructor suddenly going to pop out of the bushes and hand you a fine? Of course not. None of that bullshit is going to teach you how to avoid obstacles at speed, or predict when a speeding car is going to cross your path, or what to do if you get into a tank-slapper, or how to react if you found you entered a corner too fast.

All of those situations are what cause people to get hurt on motorcycles. Slowly tipping over in a parking lot, conversely, is typically harmless except to your pride and possibly your chrome.