Has anbody (else) been having trouble with the mechanical (Superior Labs, Inc.) tachometer in Carbon Cubs or Sport Cubs? Since 2006 I've flown many SC's and now own #132 Carbon Cub; which just experieced a (final) tach failure today. Of the several demo Sport Cubs I flew from 2006 through 2009, I had two tach issues that required replacement of the instrument in different SC's. Now, with the recent failure, it seems to be a reliability issue, especially since the tachs that failed had only about 110 hours of time indicated. I've confirmed that it's not a cable issue, having inspected and lubed it well and confirmed that it is securely attached at both ends (the cable appears "as new" when removed and lubed).
After communicating with Jason today at CubCrafters, he indicated that there is no record of a persistent tach problem, although he indicates that records may be incompete. Perhaps this general inquiry will reveal whether owners have had significant problems.
From new, the tachs seem to me to be unstable - ie. the needle fluctuates wildly at certain rpm, generally in the 1500-2000 range. Mine did that on the Carbon Cub from the get go and I recall the other Sport Cub tachs had similar issues at various rpm. Today the problem with the Carbon Cub tach indicated "0" upon engine start up and then only seemed to register "reasonable rpm indications") after many minutes (20-30 minutes of flying). This problem with my Carbon Cub tach has gone on for about 30 days now (it started by having obviously inaccurate readings upon engine start, and then sorting itself out over several minutes of operation); and finally today, the readings became unreliable at start, during flight and at landing .... during a one hour flight.
My web search suggests that the SLI tach is pretty well established and should be good, they claim a two year warranty, and has an FAA TSO "rating". I would expect more than 110 hours of reliability, wouldn't you think? My thinking is that if not a cable problem and the engine is obviously fine and running smoothly; it can only be the instrument itself.
Any other tach problems out there that might help me (and CC) figure this out?
Thanks,
Doug