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MOT advisories explained
Passed, but with a list of advisories? They're the tester's early warning. Here's what they mean, how they differ from minor defects, and what to do about the ones bikes get most often.
Advisories and minor defects: the difference
Since May 2018, MOT results sort problems into categories. Only two of them fail the bike.
- Dangerous and major defects are fails.
- Minor defects are real defects, but not serious enough to fail. The bike passes with them recorded. Fix them soon.
- Advisories aren't defects yet. The tester is telling you a part is close to the limit or will need attention soon, so it doesn't catch you out later.
Both appear on your certificate and in the bike's public MOT history, so a buyer can see them too. An advisory isn't a legal requirement to do anything, but the bike must be roadworthy at all times, not just on test day. A tyre that was "close to the limit" in June can be illegal by October.
Common motorbike advisories and what to do
| Advisory wording (typical) | What it means | What to do |
|---|---|---|
| Tyre worn close to legal limit | Tread is approaching 1 mm across the main band (bikes over 50cc). | Measure it with a gauge every few weeks. Budget for a tyre now; rears often go in a few thousand miles. |
| Tyre has slight cracking or perishing | The rubber is ageing, common on low-mileage bikes. | Check the date code on the sidewall. Old, cracked tyres grip poorly in the wet even with tread left. |
| Drive chain slack / chain and sprockets worn | The chain has stretched, or sprocket teeth are hooking. | Adjust slack to your manual's figure. If it won't stay adjusted or the teeth are hooked, replace chain and sprockets as a set. |
| Brake pipe corroded / hose deteriorated | Surface corrosion on a metal brake line, or cracking on a rubber hose. | Get it looked at. Hoses are cheap; braided replacements are a common upgrade. Corrosion that eats into the pipe wall becomes a fail. |
| Brake pads wearing thin / disc worn | Friction material is getting low, or the disc is lipped or scored. | Check pad thickness against the wear groove. Pads below 1.0 mm are a dangerous defect. |
| Wheel bearing or steering head bearing has slight play or roughness | Wear or lack of adjustment. Steering head bearings often notch in the straight-ahead position. | Have them checked and adjusted or replaced. Notchy head bearings make a bike weave and tuck in at low speed. |
| Fork or shock oil misting | A light film of oil on a fork leg or shock body. | Light misting isn't a defect. Watch for drips; a leaking seal can contaminate the brakes. |
| Exhaust or frame corroded | Surface rust, often on downpipes or hangers. | Clean and treat it. Corrosion that weakens a mounting or the frame becomes a fail. |
Wording varies between testers, and the same advisory can repeat for years. A repeat isn't automatically bad, but a tyre or brake advisory that appears on three tests in a row tells you about how a bike has been looked after. That's worth knowing when buying a used motorbike.
How to act on them
- Read the whole list on your certificate or in the MOT history, not just the pass or fail.
- Sort by safety. Tyres and brakes first, then steering and suspension, then corrosion and cosmetic items.
- Set a check date. For wear items, measure again in a month and estimate how many miles are left.
- Fix minor defects soon. They're already defects; don't leave them until next year.
- Keep the receipt. Proof that advisories were dealt with helps when you sell.
Tickover pulls advisories and minor defects from your latest MOT into a checklist, most serious first. Tick items off as you sort them, so nothing is a surprise at the next test.
Quick answers
Does an MOT advisory mean my bike failed?
No. Advisories are noted on a pass or a fail. Only dangerous and major defects fail the MOT.
Do I have to fix MOT advisories?
There's no legal requirement to fix an advisory, but the bike must be roadworthy at all times. Many advisories become fails if left.
What's the difference between a minor defect and an advisory?
A minor defect is a real defect that isn't serious enough to fail. An advisory isn't a defect yet, but the part is likely to need attention soon.
Can buyers see my MOT advisories?
Yes. Advisories and defects from tests in England, Scotland and Wales appear in the bike's public MOT history.
Why does the same advisory appear every year?
Some, like light corrosion, can stay stable for years. Wear items like tyres and chains that repeat suggest they've been left close to the limit.
Related guides
- Motorbike MOT: what's checked and how to pass
- Common motorbike MOT fails you can fix at home
- Free motorbike MOT history check
- Motorbike maintenance schedule