Reading part number

[skyshot44]

I have a Yamaha part number

5x6-11630-00 and 5x6-11630-21

I know they are for the correct bike, but I don't know what the last two digits mean. I'm assuming they are the bore size, with the -00 being stock bore.
But what would the -21 mean? .021 overbore?

Thanks for any help!!

 

[jmics19067]

I have a Yamaha part number

5x6-11630-00 and 5x6-11630-21

I know they are for the correct bike, but I don't know what the last two digits mean. I'm assuming they are the bore size, with the -00 being stock bore.
But what would the -21 mean? .021 overbore?

Thanks for any help!!

11630 is a piston kit(rings included) 11631 is the piston itself 11631-10 would be first oversize piston11631-20 would be 2nd oversize piston at an off the wall glance 11630-21 would be 2nd oversize pistonwith rings included when I get to work tonight I will double check tonight if I am not busy

 

[jmics19067]

yes it is a 2nd over piston kit with rings/pin and clips included. In all actuality 2nd oversize should be .5mm while pretty darn close is not actually .020 "

11630-20 was the original part number and was superceded by 11630-21 but I don't know why

 

[skyshot44]

Thanks for the help!!