Electric Motors, Engines & Accessories > Engines Glow Fuel > Engines R/C Glow Fuel Aircraft 2-Stroke - .76-1.2 Bookmark this Page

O.S. - OSMG0652 OSM19215 19215 531028022041 4531028022041
Manufacturer Stock#
A Closer Look at This Product
  Tech Notes

Accessories Needed

Possible Substitutions

Parts List

Easy RC: Engines

Browse O.S.

O.S. 120AX Special Engine
Click for parts for this item
O.S. 120AX Special Engine
View Larger Picture

Stock Number
FREE shipping when ordering this item on our web site... click for more information
Stock Status
Possible Substitutions

Tech Notes
This is the 120AX Special Ringed Aircraft Engine from O.S. Engines.


High performance two stroke engine designed for sport and scale
Compact size enables it to fit into most cowls
Crankshaft port timing was modified to increase power at high RPM
Velocity stack on carburetor adds acceleration at high RPM
0.1mm head gasket increases compression ratio for more power
1mm deeper machining to enlarge intake port for greater RPM
Two year limited warranty through Hobby Services beginning at date of


120AX Special Ringed Aircraft Engine, #8 Glow Plug, 70D Carburetor
with Velocity Stack, Instruction Manual, Prop Washer & Nut and
Needle Valve Extension Set


Fuel: Two-Stroke with 18% lubricant and 5-20% nitromethane
Muffler: E-5020 "Power Box"
Propeller: 15x10-12 or 16x8-10


Displacement: 1.218 cu in (19.96 cc)
Bore: 1.197" (30.4mm)
Stroke: 1.083" (27.5mm)
Practical RPM Range: 1,800 - 9,500
Output: 3.35 PS (3.155 HP) @ 9,500 RPM
Crankshaft Size: UNF5/16-24
Distance between Mounting Hole Center Same Side: 0.98" (25mm)
Distance between Mounting Hole Center Opposite Side: 2.3" (58mm)
Height/bottom of Mounting Tab/top of Cylinder Head: 3.4" (85.7mm)
Height/bottom of Crankcase/top of Cylinder Head: 4.3" (109.2mm)
Length from Backplate to front of Drive Hub: 3.9" (100.2mm)
Length from Backplate to end of Crankshaft: 5.5" (139.9mm)
Length from Backplate to Center of Crankcase: 1.2" (30.4mm)
Length from front of Drive Hub to end of Crankshaft: 1.6" (39.7mm)
Width at Mounting Tabs: 2.6" (67mm)
Width of Crankcase below Mounting Tabs: 1.8" (46.5mm)
Height from Crankshaft Center to Needle Valve: 1.3" (33.8mm)
Distance between Muffler Mounting Hole Centers: 1.9" (48mm)
Carburetor Settings;
Needle Valve, 2 - 2.5 turns out from fully closed as a starting
Mixture Control Valve, Close throttle rotor and screw in Mixture
Control Screw until it stops, then unscrew approximately 3/4 turn.
NOTE, Mixture Control Valve is factory set and should require only
small adjustments. Refer to instruction manual for full break-in

jxs 06/11/12

– If you need more information, use these O.S. resources –
Email: enginesupport@hobbico.com
Web Site: http://www.osengines.com/
Phone: 217-398-8970
  Postal Address:

Click here for Units of Measure Conversion Calculators

Accessories Needed
This is the 120AX Special Ringed Aircraft Engine from O.S. Engines. FEATURES: Modified crankshaft port timing & velocity stack on carb for more power at high RPM, compact size fits into greater range of cowls, 0.1mm head gasket for higher compression REQUIRES: Prop, fuel, glow starter, field equipment

Accessories for the O.S. 120AX Special Engine

Primary Accessories   Building & Field Equipment Optional Accessories
  Special Stock Number Product Description Parts Saver Eligible Tower's
Low Price
Click to Order Quantity Needed In Cart? Stock
 LX1608 APC 15x12 Pattern Propeller
Qty Discount Available
10.79   In Stock
 LXK129 Great Planes Silicone Fuel Tubing Standard 3'
Qty Discount Available
2.99   In Stock
 LXK134 Great Planes Ultra Precision Fuel Filter
Qty Discount Available
3.79   In Stock
 LXLPK9 O.S. Muffler Power Box 120AX
Parts Listing
58.99   Early Dec
 LXRXC4 Tower Hobbies TOWER Power 10% Airplane Fuel Quart
Qty Discount Available
9.19   In Stock
Subtotal for this Group of Accessories: 85.75  
Click to Order all items listed in this Group of Accessories    Buy This group of Accessories

Primary Accessories   Building & Field Equipment Optional Accessories

Tower Hobbies Has Been Serving Hobbyists Since 1971 • Call 800-637-6050 or 217-398-3636
See Tower Hobbies
Reviews at Bizrate.com
Hobbico, Hobby & Model Construction
Supplies - Retail, Champaign, IL
We accept the following: We accept the following payment methods: Discover, MasterCard, Visa, American Express, Diners Club International, JCB, China UnionPay, PayPal, and PayPal Credit.
Unauthorized use of any materials presented here is prohibited. Copying or reproducing any elements from this page is not permitted. All prices, descriptions and availability subject to change. Displayed within some areas of our web site, the Retail Price is suggested by the manufacturer or supplier, or estimated in keeping with standard industry practice. It may not represent the prevailing price in your area or a price that Tower Hobbies has ever offered for the item.
Copyright © Tower Hobbies All rights reserved. Do not duplicate or redistribute in any form.