holed piston :( so angry (now with pics)

[tonydevon]

ok so what causes it?

my bike was setup on dyno, run in, and I have performed a full range of plug chops twice

last weekend was the last check and it was fine, slightly rich if anything

tonight Im on way to pub doing about 55-60 and it starts to die, then came back, then died, realising it was low on fuel I knocked it to reserve with my foot, it came back to life, about a mile up the road it gave 2pops and died proper

the piston is holed, right in middle of the top, plug white and ashy looking

I cant afford to repair it all so Im scrapping whole scooter off for parts via Ebay, but any hints as to what killed it?

377 miles on brand new MEC crank, bearings, seals, delly carb muggy topend etc etc

gutted doesn't even cover how I feel

[joespeed]

whats the set up?

[psychedelicropcircle]

Nut and bolt through the hole sorted bodger style

[tonydevon]

66mm 198cc mugello kit, PM expansion, 26mm dellorto carb on MBmanifold. BGM stator, timing is set at 17 degrees,

dynoed and has run faultless,

fast flow tap, checked the flow when fitted and all was good.

I never heard any untoward noises, no seizes

[joespeed]

split rubber,blocked tap?

[RICSPEED]

i'm sure we have all been there .. just put scoot in garage a have a think ... a holed piston is almost a right of passage

[WINTERMODEL150]

As Ricspeed said Tony,put it in the garage and leave it.

Welcome to the world of lambretta's

Dean

[rosscla]

Bad luck. Take a deep breath and a day or two off it.

Which fast flow tap is it ? Did you check the flow on both open settings?

Also check for signs of blowing on the head gasket, the base gasket and round the exhaust.

You might just get away with a good clean up and a new piston.

[Donnie]

2 things.

1. You say you did a full range of plug chops twice, what exactly do you mean by that?

2. At what milage did you have the head re-torqued?

[Donnie]

Oh, and if you've holed it, it's a crank out job, there's ally in the big end and will f@@k that and the seals. dont try to skimp and get away with a quick clean jobbie.