http://cgi.ebay.com/ebaymotors/ws/eB...TQ:MOTORS:1123
anny body got a wiseco catalog? 4v5 and 25y are yamaha codes for model/year ect
4v5 is a 81 and 82 it 250 bore is 70mm stroke 64
piston for the 4v5 wiseco part number is 452
25y is the code for an usa 83 it 250 . also sold in other countries i think till 85 kinda rare maybe found in ausie or new zeland europe etc
25y bore is 68 mm stroje 68 mm
if you put the 452 piston on a 25y the piston comes out of the boe 4mm you will need a 4mm jug spacer
i own a 4v5 and may trade 1 combat wombat for a 25y and a 4v5 the owner boughta top end and tried this so i know it is 4mm too big.
take notice to what this guy is selling? a mismatched piston jug
i emailed the hess4less and he emailed me back 2 words "your wrong"
junk seller !