Axle nut size for big red

[Coaltrain]

What size is the axle nut for a 84 200es Big Red? the one that holds the wheel hub on the axle. Thanks.

[1984ATC200S]

Don't know the size but it was $2.04, Canadian, at my Honda dealer and they had it in stock. probably cheaper in the long run to get the right one form honda,