I finally got a feeler guage set from a spare parts shop for RS 140.
after opening the pack I found that it has a feeler for 0.30 mm (which i need for exhaust valve) but it does not have a 0.25mm feeler ( which I needed for intake valve) . the closest it has is 0.28mm.
Would it be ok if I use 0.28mm instead of 0.25mm for intake valve ??? Or do I need to search a more accurate feeler guage??