re the sinok problem...recently kasi my "classic" ride was also suffering from this. the culprit seems to be the cheapo fuel filter i installed. nung pinalitan ko ng orig, nawala kaagad ung problema. suspetsa ko rin na un din ang source ng backfire.


pero, like the other guys said, pa tune up mo muna; best case is it will solve the problems. worst case, it may uncover more serious problems -- but either way, you'd be on your way to solving your problems B)