Hi!
Well! To say I´m a MVVS dealer is not correct. I have been selling MVVS engines 10 to 15 years ago but not anymore, though I have some MVVS engines left.
To have the MVVS 2,5cc glow engines run well you have to use the mini-pipe and correct prop size, glow-plug and fuel.
I fly at sea level so all my engines MVVS as well as all other brands have (OS, Webra, Thunder Tigre, ASP/Kyosho (Same engines) ENYA, Rossi, etc ) are run on just 5% nitro.In fact some MVVS engines (older 15cc) cannot even stand 5% nitro.
20% Castor oil is the norm, though many of my .40 and .90 (6,5cc and 15cc ) engines, MVVS and others , are run on 15% syntetic oil (Motul "micro").
The MVVS .15 (2,5cc ) glow engine uses a Nova Rossi 5 glow plug as standard but a warmer Nova -Rossi 4 or Rossi 3 could be used too. There are naturally many more glow plugs thats works too. But those mentioned works well at sea level.
Try a an APC 7x4 and do not use any more nitro than 5% if you fly att sea level!
If you go to MVVS home page you can see what type of glow engines they still manufacture, which are not many, sad to say. Electric motors seem to taken over.