View Full Version : Rotax 503 piston damage

pat tobin
13-Aug-09, 10:03 AM
Hi all

A bit of piston damage form a 503 which I think is from a bit of the upper ring letting go. Theres no burning so I dont think its lean mixture and the plug is OK. Looks like a bit of the ring snapped and then bounced its way around the cylinder...not pretty.

But of course the question is why did the ring break.....any thoughts


13-Aug-09, 11:48 AM
Is it back or front piston?
Air or forced cooled?

13-Aug-09, 07:54 PM
Ive done a couple now similar to that over the years - they just go.....
Usually with age/lack of replacement. :confused:

pat tobin
14-Aug-09, 09:13 AM

Its the front piston (Mag side) and its free air cooled. Its been in there a while....dont really know how long. Also the tang on the spark plug was bent so it shorted against the tip.