Hi!
I have run several MVVS .90 engines , but no .77 and I have not experienced anything that you have described. All my MVVS .90 engines have run good with very easy starting , throttling and setting with no excessiv vibration at any rpm.
I have run them on both 20/80 fuel (castor oil) and on 15% syntetic (Motul "Micro") 5% nitro and 80% methanol, all with the same good behavior.
Glow plugs have been MVVS 5 (Which is a Nova Rossi plug) OS 8 and Enya 3.
Props have been small up to very large APC props (11x9, 12,7, 13x5, 13x6, 14x5W, 15x4W , 16x4W and 17x4W) all with the same good running characteristics.
Silencer used has been the new MVVS alu silencer.
I would recommend not using the small j'tec pitts style silencer as it has a too small volume that robs the engine of power.and could perhaps make carb setting more difficult.
My MVVS engines have all been equipped with the "new" MVVS 8mm carb that has a black high speed needle and a tapered idle needle. The old carb had a blunt idle needle and was a little more sensitive to set and gave a more "direct" throttle response (which is not as desirable).
