vespa head leaking

[scooter perv]

Gotta strange problem here. Mates got a polini 180 kitted px, it killed the top end one night and I noticed the head had been leaking quite badly. I rebuilt it new studs etc and within 500 miles the head had come loose. Lapped it on glass till it was dead even then loctited the nuts down...few hundred miles later it starts popping and head leaking again, this time the nuts are still tight. Im using gastight sealet but within a few miles its burnt off anyway. Its like the top of the barel is warped somehow which is strange. Next solution is to find a thin head gasket Im reckoning..any thoughts on this?

[Scooteristi]

Sounds like your compression is too high and you need a packing plate under the cylinder and/or a head gasket.

[scooter perv]

See theres not all that much compression there to be honest, even after a rebore and new piston..I asked for between 3.5thou and 4thou clearance and I think they overbored it cos theres def a hint of piston slap..anyways th scooter has been nothing but a headache to me..theres always something going wrong with the bloody thing.

[lamblast]

lap the top of the cylinder and the head then use wellseal leave the scoot for 24hrs before starting it ,this should work