Scooterotica

soullad wrote:any chance of a pic of the underside of the crown?

Diablo wrote:Are there any signs it was running hot Scotty?

top of piston all black with some carbon build
underside see pic



what do you think?

Hi Scooty
Has the barrel been ported if so how wide is the Ex port and what shape is it as it looks like the rings have been bulging out into the port and causing them to chatter in the groove, this could be the cause of the problem as the rings are wire rather than cast they haven't let go and rolloxed the cyilinder as well as the piston.
can you post some pic's up of the ex port if it has been ported as this problem might be corected by re shaping the port to help the rings and stop them from chattering ( this can only be done if the port hasn't been cut to wide ) + if you can also mesure the width strait across the port.

Cheers
Mick

I have seen the same sort of thing on a standard T5 which broke the edge off the piston and took a chunk out of the exhaust port.The scoot was only used to travel a mile or so to work but what caused it was worn out rings.

Mick Abbey wrote:Hi Scooty
Has the barrel been ported if so how wide is the Ex port and what shape is it as it looks like the rings have been bulging out into the port and causing them to chatter in the groove, this could be the cause of the problem as the rings are wire rather than cast they haven't let go and rolloxed the cyilinder as well as the piston.
can you post some pic's up of the ex port if it has been ported as this problem might be corected by re shaping the port to help the rings and stop them from chattering ( this can only be done if the port hasn't been cut to wide ) + if you can also mesure the width strait across the port.

Cheers
Mick

Hi mick
the barrel was standard but heres a couple of pictures of the exhaust port



cheers
scotty

I've seen damage like that before caused by a ring peg coming out. Are both the pegs still in Scotty?

Definately a spun ring. Either the ring has jumped over the peg pushing it back or the peg has fell out.

Seen the same damage when a mate put a piston in upside down on a Rapido.

i think a club mate might be posting on this thread soon...........

Diablo wrote:I've seen damage like that before caused by a ring peg coming out. Are both the pegs still in Scotty?

J1MS wrote:Definately a spun ring. Either the ring has jumped over the peg pushing it back or the peg has fell out.

Hi Al and Jims
managed to free top ring and yes ring peg has gone

possible race-tour piston fault? anyone else had a problem with them?
see also
http://scooterotica.org/forum/viewtopic.php?f=7&t=11215

"Mag" on the LCGB forum has posted a photo of his exhaust port, and it looks just like your photo.

I suspect he will find something amiss with his piston when he has a good look at it.

yes