sadly motokai the problem you had before may have caused some valve damage

if its stalling and hard to start you may have a leaking valve... you can test for this by giving it a compression test, which is a bit tricky with an auto decompressor for obvious reasons

so the only way is to give it a leakdown test

that is pressurise the cylinder at tdc and see if its leaking
if your lucky you may find a workshop with a leakdown tester , if not you can use any source of compressed air attached to a gutted out spark plug