Piaggio Zip 50 starting problems

[benny3008]

My 50cc piaggio zip 4 stroke is struggling to start most times, it generally takes about 5 minutes constantly holding my finger on the start button and then eventually it will fire into life, but on the odd occasion it will not start at all! :-( when i am lucky enough to hear that sweet engine sound, :-) it takes about 5 minutes for the revs to become normal, you can twist the throttle and not much will happen, it just makes a horrible grunting noise! i have reason to believe that it is due to water but it never used to be this bad, it has got worse recently, it jolts alot when riding in the rain. i think the water has damaged the spark plug but am not entirely sure, also, hen struggle to start it, the kick-start doesn't work either so i don't think its the starter motor, i'm running out of ideas, could it be the spark plug??? i cant afford to stop riding it in the rain, especially with the kind of summers we have! i never used to have this much trouble riding in the rain, it was fine but it is just in the past few months. any suggestions welcome. :-) TIA