Sa old school na cars, the carb is usually tuned na...ung nga lang kaya pangit ang takbo because: 1) madumi na ang carb and its linkages, 2) kinalikut ng walang alam, 3) electrical problem (plugs, hi-tension wires, timing ng contact point).
For the #1 - ang the best solution is to use a carb cleaner....spray it liberally until the carb is clean (read the label for directions of use). Please wear eye protection, the solvent in this carb cleaner can do chemical burns to your eyes in case of accidentally getting your eyes sprayed with it.
There are not solution for number #2....just don't dare adjusting any screws or jets in it that you don't know the function. A professional will simply adjust the air/fuel ratio...but through gut feel lang. If you have an O2 meter, then you have a better chance of getting the right stoich mix.
For number #3 - its a common problem that crack hi-tension or dirty plugs or worn-out contact points and condenser can cause bad timing. Each vechicle has its own specs, research mo muna ang info sa oto mo...you can start opening the service manual that comes with it.
hmm... pre if i were you hindi ko DIY ang pag tune-up ng auto kse pag wala kang sapat na gamit para mag tune-up bka ma gago mo pa ung makina ng auto mo..hehe sorry for the word pero baka lang.... pagawa mo nlang yan sa mechanic mo pra safe.. ok pa sana ang DIY na change oil eh.. hehe :D
onga kung magaling ung magtuturo...at kung meron ka gamit for basic tune-up oks lang tlga.. at depende rin sa tao yan eh kung ma gegets nya ung nag tuturo sa kanya..
:D