A65 piston size

[davben23]

Hi guys
Sorry for another newbie question but I've measured my bores on my A65 lightning and they are 75.70mm and the pistons measure the same but on top is stamped 100mm TD3 ? What pistons/rings would I require if I was to replace ?
Thanks in advance
Dave
Sorry should add it say 075 on the inside of the piston

[davben23]

Sorry just re-measured and bore is 75.5mm forgot to zero my gauge lol

[chaz]

standard bore size is 75mm, so as long as no significant wear or scratches you make get away with a quick flick with the hone.
as the age of the bike and likely wear  +.50mm (+.020") rings would be needed as generally first oversize now, mainly due to availability of the smaller +.010" and not really removing damage was a waste of effort . If the pistons show sign of a lot of blow by  or damage then replacement to+1mm (+.040") and a rebore and new pistons would be needed.

from experience of honing, the wear over years and any damage , the ten thou increments didnt really do a lot, my local engineer would prefer to get the pistons he needs rather than be supplied with them due to cleaning up then having to get replaced.

any other marking on the pistons would be casting numbers , the stamping on the top is generally size related

[davben23]

Thanks Chaz 👍🏻