O.S. FR7-420 Sirius7 7-Cylinder Model Engine

Tower Stock# LXZVB2  •  Manufacturer Stock# 37010
O.S. FR7-420 Sirius7 7-Cylinder Model Engine (large view)
Notes from our tech department:
This is the O.S. Sirius7 FR7-420 7-Cylinder 4-Stroke Engine.

FEATURES

Main internal parts such as the crankshaft, cam holder and reduction
gear are all plated to resist corrosion
V-shaped individual valve covers for vintage scale appearance
Impeller system distributes air-fuel mixture equally to each cylinder
ensuring high performance and smooth idle
Padded and lockable aluminum silver colored storage case
Two year limited warranty through Hobby Services beginning at date of
purchase

INCLUDES

O.S. Sirius7 FR7-420 7-Cylinder Sirius 4-Stroke Engine, seven type F
glow plugs, valve adjusting kit, radial mount & hardware kit,
needle valve extension cable, drain plug, carburetor insert, decal,
glow plug cable set, instruction manual and aluminum case

REQUIREMENTS

Fuel: Aircraft blend 5-10% nitro content with 8-10% lubricant
content (it is suggested to dilute commercially available 15%
nitromethane and 18% lubricant fuel with methanol half and half to
make a 7.5% nitro and 9% lubricant fuel)
Propeller: 22x10-12, 23x8-12, 24x8-12, 26x8

SPECIFICATIONS

Displacement: 0.6071cu in x 7 (9.95cc x 7)
Bore: 0.944" (24.0mm)
Stroke: 0.866" (22.0mm)
Practical RPM: 1,500 - 7,000
Weight: 111.7 oz (3,167g)
Crankshaft Size: UNF3/8-24
Distance from Backplate to Drive Washer: 6.2" (158.5mm)
Outer Edge of Backplate to Pushrod Covers: 4.8" (122mm)
Outer Diameter: 9" (230mm)
Carburetor Settings:
Needle valve, 2-1/2 turns open from closed position
Throttle Valve, approximately 1/4 turn open from closed position,
then start engine and follow break-in instructions on pages 19-25
in manual

jxs 06/24/10
ir/jxs

Resources
See Tower Catalog page 174.
Easy RC: Engines
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