A rebuild goes wrong in the first afternoon if the bike is taken apart faster than it is recorded. This guide is the recording. It applies to every generation in this record, from the 1993 GS to the 2006 RSV-style bike, because the crash checks and the labelling are the same job.

Make it safe, then stop

Work on a cool engine. Support the bike so it cannot fall off a side stand while you are leaning on a fairing. Disconnect the battery once you have found it. The brief does not say which side the battery is on, and it moves by generation, so that location is To verify on the bike in front of you. Do not pull the fuel line or the oil line until you have a container under it and a photo of where each pipe went.

Photograph before you undo anything

Take both sides, the front, the tail, the VIN or frame plate, the engine casting, the carburettor’s model stamp, the exhaust, the clocks, and every scuff. Those photographs are also how you tell which year’s kit is on the bike, and which body it sits on.

Number the photos to match the bags. When a connector has a choice of sockets, photograph it plugged in. A later you will not remember which socket was which.

Bag by assembly, not by “bolts”

One bag for the left fairing and its brackets. One for the right. One for the clocks. One for the front brake caliper bolts, kept separate from every other M6. Brackets differ by generation. A bee-tail duct bracket forced onto an RSV-style fairing will crack the panel and tell you nothing about the thread.

Write the generation guess on the box in pencil, then correct it when the casting is read. Pencil, because the guess is often wrong on a 1998 bike.

The condition report

Write these headings even if the answer is “not checked”:

1. Frame number or VIN, and what the decoder made of it.
2. Engine casting: Rotax 123 or Rotax 122. “Unknown” is an acceptable answer. A guess is not.
3. Carburettor stamp. The brief’s pair is a VHSB 34 with a Rotax 123 and a PHBH 28 with a Rotax 122. Haynes 4298 lists a PHBH28BD for both the 11 kW and the 20 kW columns.
4. Powervalve: blade fitted, blanking plate, or not a two-stroke.
5. Coolant: colour, level, and any oil film. The fill is about 0.9 litres of half distilled water and half ethylene glycol antifreeze for aluminium engines.
6. Oil tank and the feed lines. A two-stroke with an empty oil tank is not a test ride.
7. Exhaust: rot, and whether a 2003-on pipe still has its catalyst. You often cannot see the catalyst. Age is the clue, not a confident “it’s been de-catted” from the advert.
8. Fork seals, head bearings, wheel bearings.
9. The crash points below.

Compression ratio is 12.0:1 to 13.0:1 on a Type 122 and 13.7:1 to 14.7:1 on a Type 123. A cranking-gauge pressure is Not published. A gauge number on its own is not a pass. Torque for the fasteners the manual prints is on the torque page.

Crash damage

The brief names the checks: lock stops, bar ends and footpegs. Add the frame around the headstock and the swingarm pivot while you are there, because those are where a lowside loads the aluminium spar. A polished frame hides a crack better than a painted one. Look in daylight, not under a single inspection lamp that fills the mark with glare.

Bent lock stops mean the steering has been further round than it was designed to go. That is a frame conversation, not a new bar-end conversation.

What you should have at the end

A labelled bike, a photo set, and a page that says what it is. Only then open the engine guide or the frame guide. Ordering a piston before those two pages is how 123 parts get bought for a 122.