Carb fell off...

[Fruitjuice]

This weekend ran my Monza 225 about 50 miles on the highway to do a ride out with some friends. Had no problems getting there, no problems doing the 150 mile ride, and no 'apparent' problems riding the 50 miles back on the motorway...
Had my throttle just over half throttle on the motorway, but coming off the motor way I went over a bump in the tarmac, as I closed the throttle the bike just dies off...
Try to kick it over again, and a lot less compression and doesn't start anymore.
take off the sidepanel and see the carb hanging off the manifold but suspended right in front of it on the gear and clutch cable outers.
Put the carb back on and eventually managed to get it going again by bumpstarting it and keeping it on the throttle and made it home.
By the time I got home it actually idled but but it was definetly down on power, gutless into the headwind and only ran giving it a lot of throttle.
Thing is I never noticed anything on the motorway, and it certainly never seized, can the carb have come off earlier and still kept going without seizing, or did the damage occur in the few second it took between the carb coming off from the bump and eventually closing the throttle and it shuttign down?
I'm probably lookign at a new piston, and hopefully the barrel will be salveagable, but has anybody else had this problem with the carb coming off the manifold, and how do you solve it, reroute the gear and clutch cables?

[jonny snatchsniffer]

you might have split the rubber

[cryogenic]

What carb are you running friutjuice my carb also came off (TMX35) and was lifted off by the cables, but check to see if the float bowl nut has been rubbing on runner boards and see if the cables were forced back against the HT plug cap this caused mine to vibrate very loose and a weak spark saw the power down and i hope i`m not teaching you how to suck eggs mate but as was said before check the carb rubber is`nt split and the carb is seated to the stops of the rubber and there are no witness marks on your panels of the carb rubbing against it. As a fix i cable tied mine to the brake cable this pulled them back away from the carb Only a theory mate hope this helps

[lifes a drag]

i used to have a imola that the carb used to come off now and again , big heavy spaco , swaped it for a tm 28mm and it never came off again , check your reed valve hasnt broken or fraid on the edges as that could course it to only run on full throtle . when you fit the carb try to wipe as mutch oil of the manifold and rubber so it has a dry surface instead of a slipery one . also over tighterning the clip can course it to slip off

[Fruitjuice]

Thanks for answering...
managed to take off the barrel and piston yesterday evening...
Barrel is in near pristine condition, having only some light aluminium rubbing above the exhaust port....
The piston however is missing quite a lot of material from the exhaust port side...
I was running a kegra KRP2 exhaust, which came with only one spring for the exhaust manifold, so I think the pipe itself may not have been pulled up to the slip joint enough when revving the engine and allowed air to get sucked into the exhaust port, which slowly burned away metal from the piston. There was no other damage to the piston apart from a slight seize (probably after teh carb came off) which locked the rings and explains the loss of compression.
So hopefully it should be ok with just replacing the piston... the exhaust was on my 'to replace' list anyway as it's a little too peaky for me.
So what's the best (read: cheapest) place to get (Super) Monza 225 pistons? Cambridge Lambretta?
Don't need it tomorrow as I've refitted my old Monza 200 barrel with Wiseco piston for the time being.