PA38 as you say more that one problem but you have to start troubleshooting some place and if as i think the carb needs changing this could be the root of the problem because if it is running over rich then hot carbon deposits left in the cylinders by incompleat combustion MAY well be igniting the charge when the mags are switched off.
So a carb change and a good run at the correct mixture setting may well solve the problem.
[ 03 January 2002: Message edited by: A and C ]
[ 04 January 2002: Message edited by: A and C ]</p>