Just finished a long full rebuild on my 1974 Yamaha MX175A.
Every bearing, shift shaft, Con Rod, seals and gaskets were replaced.
Bore was left as was 1mm over bore. Just a quick hone and slap in a new piston. Waiting for a stock bore cyl I won on Fle-bay to show but I'll run it as is for now.
Back ground on the bike.
92-93 got the bike for free.
got it running on a thursday was telling a work mate and he asked if i wanted to go race it Sat. Sure why not. So off we go to the races. A "Hoot Owl" Harescramble, My 1st race ever. I'd been riding since i was 4 or 5 and traveled to all the MX tracks helping an older brother but never raced myself (well BMX but not motorized) Anyway there was 5 of us in the vintage class.
Ted (guy from work) is a well seasond racer he tells me when the flag drops don't move! WAIT lett the other classes get to the corner 1st. Okay i said. Dam the flag dropped i forgot every word he said...
As i came up to the corner WAM someone on a modern bike used me for traction!! 
Second lap I got my right foot stuck between a bodler and my brake pedal. Floded the pedal over so bad i had to remove the brake rod and pound it back with a rock.. (Think i broke my foot too. It was black and blue for a month afterward.)
Anyway whent on to win my class 
Rode the bike every once a while then meet my wife tought her how to ride on it. Raced it one more time but striped the intermidate shifter shaft. Not knowing it was outside the main case i split them. There it sat for close to 10 year on the bench and on my homemade lift while i did other things..
Well Jane asked my in Oct to get it running again.
X-mas i bought her a 74 MX250
For pictures see my site http://mysite.verizon.net/vzeyjt5o/index.html
