Check out the exploded diagrams on Partzilla - these might help pinpoint it.

OK, process of elimination. 100 percent it's the idle speed rod that lifts the slide. Comes up through the vertical adjuster with a small split pin folded around. Is there I prize for the correct answer haha or just a prize know it all lol.

That's exactly what I was thinking RT325...  idle speed rod. 

#25 here www.partzilla.com/catalog/yamaha/motorcy...1966/ygs1/carburetor

Found it!! It’s the throttle bar. PN 127-14114-00-0. Part of the carburetor.

You guys are amazing. Picture would have been worth 1000 words!

Gotta be old to remember things like that as Mark knows haha. Bar throttle they call it just to be different. Talking your ygs1 & disc valve I replaced more than a couple of those on the yg1t, same disc with a bit less duration on the farm model. The fiber came loose on the steel center then eventually started free wheeling. Then you wonder why it's extremely underpowered.

test pic

Trying picture again

copying link here:


also adding attachment 

Get this message each time I try.

MessageThe links or images has been removed from your message because you aren't allowed to add

Someone on Youtube might show how to add pics to a forum like this. If youtube goes too fast ya can slow it down on the star wheel along the bottom to as low as .25 usualy. Cheers.