Honda NOS CB400, CM400, 1978-81, Standard Piston & Rings, # 13101-417-003 (13101-417-013), 13011-413-025. 

Look at photos carefully.  Confirm fitment via part number with your manual and/or dealer.  Part may fit other models or years.  We will combine shipping for multiple items.  We offer two options for shipping, for most listings.  See shipping details.  Please, contact us before leaving any unfavorable feedback.  We strive to provide excellent customer service.

Part # = 13101-417-013
Part Description = PISTON (STD) - (replaces 13101-417-003)
Model Count = 4
CB400A 1978 400 CB400A Hondamatic Street 
CM400A-A 1980 400 Hondamatic 400 Street 
CM400A-B 1981 400 Hondamatic 400 Street 
CM400A-Z 1979 400 Hondamatic 400 Street 

Part # = 13011-413-025
Part Description = RING SET (STD) 
Model Count = 16
CB400A 1978 400 CB400A Hondamatic Street 
CB400T-A 1980 400 Hawk 400 Street 
CB400T-B 1981 400 Hawk 400 Street 
CB400TI 1978 400 Hawk I 400 Street 
CB400TII 1978 400 Hawk II 400 Street 
CB400TII-Z 1979 400 Hawk II 400 Street 
CB400TI-Z 1979 400 Hawk I 400 Street 
CM400A-A 1980 400 Hondamatic 400 Street 
CM400A-B 1981 400 Hondamatic 400 Street 
CM400A-Z 1979 400 Hondamatic 400 Street 
CM400C-B 1981 400 CM400C Custom Street 
CM400E-A 1980 400 CM400E Street 
CM400E-B 1981 400 CM400E Street 
CM400T-A 1980 400 CM400T Touring Street 
CM400T-B 1981 400 CM400T Touring Street 
CM400T-Z 1979 400 CM400T Touring Street