Use the Right Phillips Screwdriver for your Japanese Bike
Oddly enough, the cheesy Phillips shank found in most older Japanese motorcycle tool kits works especially well on these old case screws. Small carburetor screws and the tiny ones holding brake reservoir lids in place seem especially prone to stripping. To prevent stripping, invest in a selection of good quality Phillips screwdrivers – this is not where you want to economize. Get a quality tool in the common #1, #2, and #3 sizes used on motorcycles.
If you see that there is a small dimple or punch mark on the screw head, you are dealing with a Japanese Industrial Standard (JIS) fastener. For best results here you should use a JIS-spec screwdriver, they are not hard to find in Thailand.
If you are a dedicated tool guy or you work on a lot of older Japanese motorcycles, make the extra effort to search for JIS screwdrivers. Always make sure that the tip fits the fastener snugly, and the tool still has sharp edges to securely engage the fastener, and even the most stubborn screws should back right out.