Hi Will, thank you for those kind words!

The engine is the MVVS 91 rear exhaust with some modifications. The stock engine is designed to run on 0-5% nitro so I had to do some modification to run 15% nitro. I have added three extra shims in addition to the one provided with the engine. The glow plug which gives the best throttle response and power is the OS #F with two gaskets. The stock 8mm carb dose not work very good in an inverted position when the engine is loaded down with an APC 15x8 prop. It can handle a 14x8 prop but any more it suffers from midrange problems with dead sticks as a result. After 20 flights, all dead sticks, I swap the carb with a Perry pump carb #9100 and a Perry pump. This carb works flawless. I have glued the carb into place with 5 min epoxy to prevent air leakage. The exhaust is Hatori # 700 muffled tuned pipe set at 22 inches from glow plug to the first baffle in the pipe. This set up gives 8700 rpm on the ground and my 7,8 Ib Sky Star 90 unlimited performance in the vertical. The engine is mounted in a home made “Hyde mount” with nose ring support. The power of the MVVS 91 is almost identical to the Super Tigre G90.

If I had known how much trouble I had to go through to get the MVVS to work I would have purchased a YS 110 instead.

Regards,
Henning