Callahan, I'm gunna go out on a limb here, 2 stroke rotax engines are similar to 2 stroke motorcycle engines, with you breaking down and rough running issues I just wonder, Had an old BSA Bantam years ago and had a heaps of issues over a period of time, myself and mechanics couldn't solve it, went for a long ride one day and got so bad I had to stop luckily it was near an old fashioned bike shop, the old guy had me up and running in quick time and just a few bucks, seemed the capacitor in the points was faulty and once fixed ran smooth as, as the Rotax 503 has two capacitors just wondering if that is part of your running smooth issues. Showing my age on this is irrelevant lol [/url]
I have a 503 in pieces here and checked the ignition system and has two capacitors
31 in diagram is the two capacitors
Bosch ignition, Rotax 503 Bosch points ignition, Rotax points, Rotax condensors.