Yamaguchi Findings

I've decided to make a post that I'll try to update occasionally with things I've found on the Yamaguchi that I wasn't able to find anywhere. So here we gooo!

 Piston specs!
Garelli NOI and VIP pistons are near match for a replacement to the stock Yamaguchi piston. The Garelli pistons use a 12mm pin though, which isn't a problem if the connecting rod is replaced with a suitable replacement.  

Con rod specs!
Big end pin is 18x33mm
I had a NOS Hodaka pin turned down by a machinist to 33mm.
Big end bearing is 18x23x11.8, good luck finding one though!
Hodaka (Ace?) big end bearings are the same however if you can find one of those.

UPDATE- I pressed apart my crank to find pitting on the ID of the big end of the rod, making it unusable. However, I've found a connecting rod that will work as a replacement. The rod is a Honda DIO rod. It is 4mm longer length however, so a base spacer will have to be made to keep things correct. PRO-X sells a nice aftermarket rod that I've ordered. (PRO-X part number 03.1010). Now the Garelli NOI/VIP pistons work with a needle bearing. Win Win Win.

New big end pin cut down to length on the lathe.

PRO-X Honda DIO rod pressed into the Yamaguchi crank halves

Stock port map!

Engine bearings!
1 - 6004
1 - 6302
2 - 6202

Engine seals!

1 - 25x38x6

1 - 19x42x6.5

1 - 15x30x7