Senior Telemaster Build, Power and Fuel ( Part Six)

Photo by D. Reifsnider

In part six and the last in our series on building the Senior Telemaster, I'll briefly go over the engine and fuel system that I have used in this plane. For a power plant, I chose the O.S. 91 FS Surpass II. With it being a four stroke, it's a little heaver than what the designer had intended, but still a tried and proven engine for this plane.

SPECIFICATIONS
Stock Number: OSMG0890
Displacement: 0.912 cu in (14.95 cc)
Bore: 1.091 in (27.7 mm)
Stroke: 0.976 in (24.8 mm)
Practical rpm: 2,000-12,000
Output: 1.6 hp @ 11,000 rpm
Weight w/muffler & manifold: 23.9 oz. (678 g)
Weight w/o muffler & manifold: 22.2 oz. (630 g)
Recommended Props: Stunt: 11x10, 11x11, 12x9.5, 12x10, 12x11; Scale: 13.5x8, 14x7, 15x6, 16x6, 12x8 3-blade, 12.5x7 3-blade

I chose to run a Master Airscrew 15x6 K Series G/F Nylon Propeller. The fuel tank is a Sullivan Slant Tank 12 oz. that is surrounded by foam rubber so that it sets at the top of the fuel tank compartment.

Fuel Compartment

Silicone fuel tubing is routed through the firewall with the supply line being equipped with a Great Planes Ultra Precision Fuel Filter. Homemade barbs were added to the copper fuel lines exiting the tank by wrapping the ends with fine copper sire and then apply a bead of solder over the wire. All internal lines were then secured with Great Planes wire fuel line clamps.

The throttle linkage consists of a Sullivan Gold-N-Rod from the Hitec HS-485HB servo out through the firewall where I used a Du-Bro # 665 4-Stroke Throttle linkage system for connection to the carb. The Du-Bro linkage was needed as the carb on the OS is rear mounted and sets very close the the firewall and does not leave enough room to mount the linkage directly.

Installed Throttle Linkage

I hope you have enjoyed this article as much as I enjoyed building this classic RC airplane. To close it out, I'll leave you with a video of some engine testing that was done prior to getting this lady airborne.

1. Part One, Wing
2. Part Two, Tail Feathers
3. Part Three, Fuselage
4. Part Four, Wing Struts
5. Part Five, Wing Attachment
6. Part Six, Power and Fuel <-- YOU ARE HERE