Malossi 210 piston hole

hi..ive just got a 97 px 200 with malossi 210 and long crank,28 dellorto,jl righty,t5 top gear ..etc..i was on a road trip and holed the piston(doing 105kmph)anyone with any ideas why this happened and/or how to stop it happening again....also,what repairs am i up for...top end rebuild or just new piston or other?( plug is a ngk b7es...engine done 1200 km)

Ok , so let me get this straight - you have just bought a kit and bolted it on to a standard P200 motor ?

If so did you change the main jet as supplied with the kit ? Standard would be a 116 or 118 depending on the year and model of P200 , the kit has a 130 jet included.

Standard timing will have been anything from 21 to 23 degrees BTDC depending on the year made, your kit needs 17 or 18 degrees BTDC ( 125cc settings).

You don't HAVE to drop the motor but it does make the job easier and especially as it allows the engine casings to be matched to the kit to get the best from it.

Where are you from ?

hi ty..i just got the scoot...dont know about timing, its got the head that came with the 210 malossi kit...as its new to me i dont know about the jets or an air leak,...is it stupid for a beginner to attempt this job?(i have to drop the motor,dont i?)

Do you have a Scooter Club in your area ? I am concerned that the shop who built it cannot tell you the jetting they used - this is not good practice.

My advice is to find your local club and ask for help - you'll usually find lots of technical knowledge and experience is offered for free or the cost of a beer .

thanks m8..ill do that..happy scooting

A couple of suggestions and then a couple of questions.

B7ES is ok for around town but for longer trips use a colder B8ES plug.

If the barrel is scored then change it , if its ok and just the piston is damaged then just change the piston - make sure you buy the correct grade of piston to match the barrel.

What timing setting are you using ? You should set to PX125 mark or very slightly later.

What jetting are you using ?

Is it possible there could have been an air leak weakening the mix?

What cylinder head are you using ?

i just bought it fully worked from  a shop...i am getting the bikes details..but they dont have the jetting details.