As some have noted, MT's service bulletin 31 (
http://www.mt-propeller.com/pdf/sbs/sb31.pdf) says the MT governor flyweight failure problem applies to engines "modified with electronic ignitions or higher compression pistons." At least one of the RVs that had an MT governor fail had dual magnetos and stock pistons. It's been reported on VAF that this has been brought to MT's attention. MT has not changed the service bulletin in the intervening months.
Based on MT's unwillingness to honestly describe the failure condition in their service bulletin, I lost confidence in MT and pulled the MT governor from my plane in January. I replaced it with a PCU 5000, which has noticeably better performance than the MT governor (the PCU doesn't have the rpm hunting that the MT had).
At OSH this year, I spoke with MT about the fact that their SB is misleading, in that there have been failures in engines without either electronic ignition or high compression pistons. It was amazing to hear the blamestorming from the German-accented MT rep at OSH. "What about McCauley governor failures" "What about Whirlwind propeller failures." I pointed out that the issue at hand was MT's failure to publish an honest, complete service bulletin. The MT rep continued to attack other products, rather than address MT's Service Bulletin shortcomings.
I'm glad I got rid of the MT governor on my plane several months ago. Based on the behavior of MT on this issue, I'll advise all prospective builders I meet not to use MT products.
rev limiter
Linear Mode
