What has happened to this piston?

[scooty]

Firstly this happened on the way home from cobblesoul run.It ran fine there and for the wkend on the way home another lad had a siezure so we pulled up to let it cool a little, anyway got his running and mine wouldnt run changed a few things took flywheel off seemed ok changed plug lead cap and cdi still wouldnt run so we bumped it and it ran but only above 3000rpm much to the annoyance to the passport control at the ferry port when i didnt want to shut it off
my set up is
TS225
tm35
pm pipe
v force reeds
static timing 18 deg
so what could have caused this to happen to my racetour piston?




cheers
scotty

[a.lo]

judging by the blowby the rings they or the bore is worn out, not sure about the other bit though. is there a split in the ring groove?

[scooty]

its blowing past the bottom ring because its stuck in due to whats happened to the top ring?
not slplit just worn out of shape the top ring can be moved up and down in that area
only done a couple of thousand miles on new piston and replate

[guygrrr]

looks like the ring got caught inna port. but rather then snapping, as it's wire drawn, it tried to pull the top of the piston off. did you check yr bore for damage? are the ports properly chamfered?

[soullad]

any chance of a pic of the underside of the crown?

[scooty]

looks like the ring got caught inna port. but rather then snapping, as it's wire drawn, it tried to pull the top of the piston off. did you check yr bore for damage? are the ports properly chamfered?

all ports where chamfered but it has worn one side of the exhaust port away on the barrel

[scooty]

any chance of a pic of the underside of the crown?

will try and get some posted

[Diablo]

Where did you get it replated?

[scooty]

Where did you get it replated?

langcourt Al
Forgot to say dynoed at diablo

[Diablo]

Are there any signs it was running hot Scotty?