Scooter fault log — the record that makes diagnosis possible

The problem it solves

Intermittent faults are the hardest to fix and the most badly reported. By the time the machine is in front of somebody who could diagnose it, the owner remembers that it "sometimes cuts out" and nothing else — not what the weather was, not how far into the ride, not what had been done to it the week before.

Every diagnostic sheet in this library works from observations. This one is where the observations live between sessions, and it is the difference between a fault you are chasing and a fault you are guessing at.

The two columns people leave out are the ones that solve intermittents. **Conditions** — cold or hot, wet or dry, first mile or twentieth, uphill or flat — turn a random cut-out into a pattern that points somewhere. **What changed** catches the fault that appeared the week after a job, which is a category that accounts for a surprising share of them.

It is also what you hand to somebody else. A page of dated entries with conditions is worth more to a mechanic or a forum than any description you can give from memory, and it costs nothing to keep.

The mistakes this sheet exists to prevent

• Recording the symptom without the conditions, which is what turns an intermittent into a mystery.
• Not noting what had been worked on recently, so a fault caused by a previous job looks random.
• Recording conclusions instead of observations, which cannot be re-examined later.
• Only writing it down when the fault is bad, so the pattern of when it is fine is lost.
• Keeping it on a phone rather than with the machine, so it is not to hand when the fault happens.

How to use it

1. 01Keep it with the machine, not indoors.
2. 02Write an entry when it happens, not at the weekend.
3. 03Fill in the conditions even when they seem irrelevant. The pattern only appears across entries.
4. 04Log every job you do as well, on the second table. Faults that follow work are common.