The ignition system of my Rotax 912 80 hp [Flat four cyl. FOUR stroke] Rans S6 mysteriously packed up after running a bit rough.
Radio'd the local a/field who I was on listening watch with. They offered me a glide in but from 2,000 ft. I knew it wasn't near enough. Spotted a large enough field approx. same size (like they say) as my base strip and windmill glided in without bending it onto a rather rough tussocky surface.
Agreed it's not a quick a/c so relatively easy to get her in compared with many types discussed above. [Couldn't find anything wrong & flew out a while later].
It took over a year of step by step investigation of all the usual suspects to get rid of the occasional rough running which we now believe was caused by carbon/soot build up inside from running a bit too rich at partial, therefore cruise, throttle for some years before I bought the 'plane. One cylinder suspiciously had lowish compression.
A new Bing carb. needle and its jet, eventually did the trick. This Spring a couple of EGT probes were installed to ease my mind on mix effects. Running it harder 4,900 - 5,000 rpm as recommended by the Rotax forum 'guru' seems to have helped too & (possibly) burnt off any imagined deposits.
Nowadays all four compressions are excellent and the English Channel crossed x4.
mike hallam.
Last edited by mikehallam; 1st December 2012 at 16:02.
Reason: added '4-stroke' & sp. correction to 'suspects'.