PEUGEOT 100cc hole in piston

blaze187 · L Plate Warrior Joined: 05 Jul 2010 Karma :

hiya everyone
im rebuilding a 100cc peugeot 2 stroke at the min and its blown a hole in the top of the piston dus anyone no y this may of happend someone told me it could be a cdi problem could this be true

radical · Spanner Monkey Joined: 02 Jul 2010 Karma :

Possibly running too weak (petrol/air mix) and/or incorrect plug, is the exhaust system standard or aftermarket?

MaybeGuy · Super Spammer Joined: 12 Mar 2007 Karma :

new exhaust without being jetted for it.
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!! Mr. Green

Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

blaze187 · L Plate Warrior Joined: 05 Jul 2010 Karma :

its all standard . thanks il have to have a look at that

radical · Spanner Monkey Joined: 02 Jul 2010 Karma :

Op check that the air filter is intact as if it is missing or the air box has been modified without rejetting the carb this would also make the bike run weak and cause the holed piston.

stevo as b4 · World Chat Champion Joined: 17 Jul 2003 Karma :

It's quite unusual on a std one for that to happen. maybe there was an air leak somewhere that let it run too weak? These type of faults can be hard to find, if it's not the filter-carb-inlet manifold causing the problem.

On my SF100, i melted the sides of the piston, about 40miles after having fitted a modified head that increased the compression ratio. i still don't know to this day exactly what i did that cured the problem with the new top end i fitted, as i used a 1grade cooler plug, went up one size on the main jet, and used 98RON fuel often with a drop of octane booster for good measure.

blaze187 · L Plate Warrior Joined: 05 Jul 2010 Karma :

thanks for all your help just got abit worried when got told it was the cdi il give it all a good look over now .

blaze187 · L Plate Warrior Joined: 05 Jul 2010 Karma :

iv had a look at it now and found 2 screws missing from the bottom of the air box and the air filter pushed to one side do you think this could of been the prob

radical · Spanner Monkey Joined: 02 Jul 2010 Karma :

It could well have caused the problem as the increased flow of air would have weakened the mixture which would cause a holed piston if the main jet in the carb had not been increased in size to compensate for the missing filter.