What Size is that bolt ?

by Terry Campbell

Many people are not aware of the relationship between Yamaha part numbers and sizes of some fasteners. Knowing that this relationship exists can sometimes save you a tremendous amount of time and hopefully prevent you from ordering something you don't really need when replacing or upgrading fasteners.

The best way to explain how this works is to use a real fastener; in this case a bolt, as an example. The top shock bolt on the Vmax is Yamaha part no: 91314-08020-00. If you look carefully at the center set of digits, (-08020-), they are not likely to do a thing for you unless you happen to know in advance that this bolt is 08mm in diameter and 20mm long ... get it ??!? ... "08020" is an 8x20mm bolt!

OK .. stop staring into space ... lets do one more. The bolts that hold the end plate on the clutch are Yamaha Part no: 97017-06025-00, so this bolt is 6x25mm right ? All right .. one more but only because you really have to learn this. The screws that hold the end caps on the carburetors are Yamaha part no: 98580-05012-00, so if you think these screws are 5x12mm you are absolutely correct.

This relationship is not accurate 100% of the time. There are some fasteners that have special qualities that will use the center digit alone or the entire string for other purposes. Keeping that in mind this information will hopefully make life somewhat easier the next time you are wondering "what size is that bolt?"