ur plug might b ok but wat bout ur cable? is it giving enough fire to ur spark plugs o not to produce the firing? ignition timing can be checked wit the timing light at the work shop... no timing light cant check it
mine leaked... no oil.. so difficult to start. it's like the starter motor sucked all the energy it could get from the battery... service the starter motor cost RM50
can check for starter motor wirings as well.. some say add relay can get easier start.