Decoding Suzuki Part Numbers
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Suzuki part numbers for these models generally follow the format of two groups of 5 digits - as example:
- 41591-31000, which is a front engine mounting plate
Sometimes a colour is specified in the original part number which can be helpful, but often isn't as there is no cross reference from the old Suzuki paint codes to anything you can buy today. Where it is useful though is in those cases where a generic black or semi-gloss/satin black are specified - for example:
- 41100-31601-019 is the frame number for the 1972 J series GT750, and the 019 at the end shows that it came in gloss black.
The part numbers can be further decoded as follows:
The problem is there are always exceptions, and Suzuki sometimes didn't change the part number even though the item had changed - fork gaiters are a good example where 51571-33030 was an 11 pleat item for the model J, and an 8 pleated item for the model K. Likewise for parts assemblies, supposedly the eighth digit is supposed to always be an '8', however if you look at the turn signal assemblies and the tail lamp assemblies you will find they are have a '6' or a '1' in the eighth place. Spoke sets have the '8', as do wheels so it seems to be 'hit and miss'.
While the tank, side covers and other painted parts have their year specific colour codes, probably the most common colours seen with part numbers are:
- 019 which is gloss black
- 291 for semi gloss/satin black
For a more complete list of colour codes used for the GT550 series, please ##see this page##.
Likewise you can usually tell a fastener diameter from the part number (but not always). For example:
- 02111-05207 - the '05' indicates it is a 5 mm diameter screw and the '20' shows as being 20 mm long.
This can be useful when buying generic stainless steel fittings, although you still have to confirm the length as the numbering is inconsistent for length, especially with longer bolts. For example, 09100-10035 is a 10 mm bolt, but it's 100 mm long. Another issue is trying to sort out the finish and whether an 'S' head bolt was used - 01000 prefix bolts are supposedly plain heads, and 09000 supposedly are the higher tensile 'S' head bolts. Both were changed to have a '4' and a '7' on the heads respectively during the 1977 GT550B production as per USA Suzuki bulletin 'General-25' which can be viewed at this link. However, if you check the engine crankcase bolt part numbers, most of them came with 'S' heads, but are listed as being standard.