Glow Plug--Fuel--Prop Recommendations
 

I recently acquired a used Hobbico Superstar 40. This is my first plane and although it wasn't my first choice, the price was to good to refuse (free). The plane has been crashed but seems to have only minor damage. I'm sure that I will have a good many questions once I start working on the plane, but for now I'm focusing on the engine. It is an OS40LA. I have removed it from the plane and I would like to bench test it to make sure it runs properly. I would like to know the correct glow plug, fuel (oil type/% & nitro %), and prop to use. Thank you for your assistance.

Glow Plug--Fuel--Prop Recommendations
 

The OS 40 LA's like anywhere from 5%-15% nitro. Use a fuel that has some castor in it. As for total oil content this is debateable depending on which fuel you are using. Some fuels have a higher viscosity oil in them so you might not need as much oil. I always use Wildcat 15% nitro, 18% totaly synthetic oil, then add about 4 oz. of Klotz Castor to it to bring the oil content up to 20%. This may be overkill, but I haven't had any problems due to lack of oil, and the engine (OS 46 SF in this case) has plenty of power.

Glow Plug--Fuel--Prop Recommendations
 

You're doing something more people should do...bench run your engine to get it set...then...put it on the plane ;)

For fuel, 10% nitro 20% lube is just fine, pop an OS #8 (or A3) in the head and strap an APC 11x4 up front...bingo...there you have it. Your plane will do just fine with that combo...plenty of thrust, yet a lower top speed...just what you need for a trainer.

Glow Plug--Fuel--Prop Recommendations
 

Sorry forgot to recommend the plug. Here's another vote for the OS #8.