O.S. GF40 4-Stroke Gas w/Muffler

Tower Stock# LXCZLF  •  Manufacturer Stock# 39400
O.S. GF40 4-Stroke Gas w/Muffler (large view)
Regularly Purchased Together
Although customers also purchased these, compatibility is not guaranteed. Click an item for product details.

Notes from our tech department:
This is the O.S. Engines GF40 4-Stroke Gasoline Engine.


Ideal for aerobatic or scale aircraft
Same firewall mounting system as the O.S. GT33
Walbro carburetor witn integrated choke rod guide that simplifies
installation, choke rod guide is integrated with backplate
Positive Crankcase Ventilation (PCV) helps keep model and environment
cleaner without blow-by gas and oil waste
Two year limited warranty through Hobby Services beginning at date of


GF40 4-Stroke Gasoline Engine, CM6 Spark Plug, Muffler, Ignition
Module and Instructions


2-cycle oil, see SPECS
Ignition Battery: 4.8-6.0V NiCd or NiMH, 6.6V LiFe or 7.4V LiPo pack
LiPo battery requires voltage regulator
Propeller: 18x8 for break-in, 18x8-12, 19x8-10 20x8-10
Mounting standoffs, length depends on aircraft
Gasoline safe fuel tubing and fuel filter


Displacement: 2.438 cu in (39.96 cc)
Bore: 1.57" (40mm)
Stroke: 1.251" (31.8mm)
Practical RPM Range: 1,800-9,000
Weight: Engine, 42.3oz (1200g)
Muffler, 4.0oz (113g)
Ignition Module, 3.4oz (95g)
Gasoline/Oil Mixture: 30:1 - 50:1
25:1 fuel/oil mixture if brand of oil states 50:1 mix
Crankshaft Size: UNF5/16-24
Length from Backplate to Drive Hub: 4.7" (118.5mm)
Length from Center of Crankcase to Drive Hub: 3.1" (78.6mm)
Length from drive hub to end of Crankshaft: 1.6" (41mm)
Length from Carburetor to end of Crankshaft: 7.8" (197.6mm)
Height from Center of Crankshaft to Rocker Cover: 4.9" (126.7mm)
Height bottom of Crankcase/top of Rocker Cover: 6.2" (157.2mm)
Distance between Vertical Mounting Hole Centers: 2.1" (54mm)
Distance between Horizontal Mounting Hole Centers: 2.7" (70mm)
Width of Cover Plate: 3.3" (83.7mm)

jxs 05/01/13

See Tower Catalog page 173.
Easy RC: Engines
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