Grand Junction, Colorado
Well as strange as it maybe. The #8 plug is hitting the top of the piston. A3 is actually a #6. I have rebuilt the OS .55 many times. Rebuilding is not out of the question though. But I don't think the engine being worn, would cause it to just quit at 1/2 throttle but run perfect at idle to half throttle and just quite without a burp! There is probably something going on with the carb. Removing the needles and blowing out with some carb cleaner may do the trick. Presently most dealers are showing the ring for the OS 91 backordered until late June. But if rebuilding it comes to that is lot better option then buying a new engine. Man the 105hz seems to be a awesome engine, but quite pricey. The OS 105hz will probably be option later on. But presently finances won't allow it. I got the heli free from a friend or did I?? Once I get all the kinks work out, it will be a awesome heli.