I remember loctite being promoted for the first time in the mid-1970's when I was a kid...  It was kind of of a "miracle" magic trick stuff because it stayed liquid until air was removed.  It wasn't in common use though.  Sales guy was trying to sell it to my Dad for the truck shop.  Became more common in the early 1980's if I remember correctly. 

What we used as "threadlocker" was recommended in magazines...  "gorilla snot" which was 3M weatherstrip adhesive in the white and red tube.  Sticky yellow stuff.  Worked good.  Had it all over my bikes (and fingers and clothes...  hahahaha)

I don't recall Loctite being spec'd in Yamaha manuals until maybe the 1990's?  Would be interesting if someone knows when.

Anyway, I just looked up the history and Loctite was a new company in 1964 and really didn't even try to enter the "automotive" market until 1968 so the chances that your YCS1 had some from the factory are pretty much zero. 

Got my new JIS bits and all is well. I did learn 1 very valuable tip. Tap the bit into the screw to seat it. Makes a difference. Thanks to everyone. 
This bike is becoming a good learning experience.  Everytime I fix one thing I find another. Put a new tube in the front tire and found a bent brake rod. Seemed straight forward easy to fix. I cannot figure how to remove the pins that hold the rod ends (#30). Any ideas?Got my new JIS bits and all is well. I did learn 1 very valuable tip. Tap the bit into the screw to seat it. Makes a difference. Thanks to everyone. 
This bike is becoming a good learning experience.  Everytime I fix one thing I find another. Put a new tube in the front tire and found a bent brake rod. Seemed straight forward easy to fix. I cannot figure how to remove the pins that hold the rod ends (#30). I felt for cotter pin and scratched around with a pic.  Any ideas?

I can't remember, but just remove both brake arms together along with the linking arm & will be plain to see. Do you need to remove it for a reason or can you just tweak in in place.

I might be able to tweak it some but did not want to break anything. I removed the pinch bolts but could not get the arms to budge. Maybe needs a little more persuasion. Thanks!

Yes just tap a screwdriver in the gap to slightly spread it-loosen it on splines. You wouldn't break anything tweaking the rod though. I'd just unlock the rod nuts & revolve it to the high point & give it a tap straight. Just me though. good idea though to lube the shoe cam shafts while ya in that area though.

Thank you for the guidance. 

Back on this bike. On the clutch pressure plate screws is snug tite good? 
On the crank case cover screws what is the correct way of tightening these. I hand tighten and 1 hit with impact driver. Never had a problem just want to be correct. 

Thanks!

Pressure plate screws, yes snug is good. In my opinion tightening covers with hand impact driver is over tightening them, but I could be wrong.