Wish I knew this earlier now and not later in life.
Anyone else know this squirrel?
JIS screwdrivers and screws.Handy to know.
https://www.motorcycle.com/ask-mo-anyth ... llips.html
Woulda saved a lot of carby bowl butter screws and neighbours covering their ears.

I only learned the difference when I started flying RC helicopters. Needless to say, you crash while you’re learning. The smaller the screw, the more important it is you have the right screwdriver.

For the decades preceding my eventual acknowledgement that there was a difference, I just thought Japanese bike used crappy Philip head screws..lol

Never seen a JIS screwdriver in the US that I know of. Are they readily available and you just have to ask?

I use these Vessel Screwdrivers from Amazon. They work great.
https://www.amazon.com/s?k=vessel+screw+drivers&crid=361EZ56XT329Q&sprefix=vessel+screw+driver%2Caps%2C118&ref=nb_sb_noss_2

wacky stuff

On all the screws and even the bolts on AVT engines I give the heads a lite tap with a really small brass hammer to shock the threads before turning, with age they all develop a little corrosion or dirt gets in makes them stick.

Just a lite tap you do not want to damage the heads.

Happy to read this! Fantastic facts and the grade of detail provided is wonderful!
Thanks all!