Shopping Cart
Shop Now...
R/C Hobby Products
Additional Hobby Products
Shop by Brand Easy Pay Shop for Parts
New Items
Special Sales
  Electric Motors, Engines & Accessories > Engines Glow Fuel > Engines R/C Glow Fuel Helicopter 2-Stroke - .52 & Up Bookmark this Page

O.S. - OSMG1982 OSM18645 18645 531028021419 4531028021419
Manufacturer Stock#
A Closer Look at This Product
  Tech Notes

Accessories Needed

Replacement & Optional Parts

Easy RC: Engines

Browse O.S.

Manufacturer's Product Web Page

O.S. 91HZ-R 3D Speed Black w/Powerboost Pipe
Click for parts for this item
O.S. 91HZ-R 3D Speed Black w/Powerboost Pipe
View Larger Picture

Tower Catalog Page: 198

Stock Number
Retail Price
Tower's Low Price
Stock Status
In Stock
Limited Quantities

Buy Now
Add to wish list
—— Share ——
Share on Twitter
Share on Pinterest Email This Page To A Friend

Quantity Discount
  Special Savings When Buying in Quantities
Special Stock Number Units at this Price Tower's Low Price Click to Order Quantity Discount Savings
O.S. 91HZ-R 3D Speed Black w/Powerboost Pipe Add to Wish List
1279.68  Buy Now 60.30  

Tech Notes
    This is the O.S. Engines 91 HZ-R 3D Speed Helicopter Engine in Black
                      with the 91 PowerBoost Tuned Pipe.

****** Because of the competition nature of this engine,****** ******it is NOT covered by the O.S. 2 Year Warranty.******

FEATURES: Designed for all-out 3D competition DRS (Demand Regulator System) ensures a steady fuel supply for 3D flights 165 exhaust timing for optimal horsepower and stable hovering Newly designed combustion chamber shaped to match the big bore carburetor and advanced exhaust cylinder timing 61G Big Bore twin needle carburetor is designed to develope stable horsepower at 70-80% throttle which is widely used in 3D flight PowerBoost pipe is constructed of polished natural finish aluminum and was developed exclusively for flights with 90 size helicopters

INCLUDES: 91 HZ-R 3D Speed Helicopter Engine, with PowerBoost Pipe, Exhaust Tube and Mounting Hardware, #8 Glowplug, Check Valve, 0.2mm Head Gasket and Instruction Manual

REQUIRES: Fuel: 10%-30% nitromethane with at least 18% lubricant. Lubricants may be either castor or synthetic oil or castor/synthetic blend. Field Equipment: glow starter, fuel bulb, fuel can filter, fuel pump hexagonal starting shaft (depending on brand of helicopter) electric starter, battery and fuel tubing

SPECS: Engine- Displacement: 0.91cu in (14.9cc) Bore: 1.091" (27.7mm) Stroke: 0.976" (24.8mm) Power Output: 3.6hp / 15,500 RPM Practical RPM Range: 2,000 - 16,000 Weight (w/o Muffler): 21.27oz (603g) Crankshaft Size: 5/16-24

Carburetor Adjustments- High Speed Needle Valve: Turn approximately 30 (3-4 clicks) during initial adjustments, then approximately 15 (1-2 clicks) when making final adjustments Medium Speed Needle Valve: Turn approximately 30 (3-4 clicks) at a time Idle Mixture Control Screw: Turn approximately 5 at a time, turn left to enrich idle mixture and right to lean mixture Height from crankcase bottom to top of cylinder head: 3.9" (100mm) Height/bottom of mounting tab to top of cylinder head: 3.1" (79mm) Distance between mounting holes same side: 0.98" (25mm) Distance between mounting holes opposite side: 2" (52mm) Distance between muffler screw holes: 1.6" (42mm) Distance/bottom of mounting tab to muffler screw holes: 1.8" (42.8mm) Distance throttle lever to center of engine: 1.6" (42mm) Length from front bearing to center of engine: 2.2" (56.4mm) Length from front bearing to backplate: 3.3" (83.8mm) Length from backplate to end of crankshaft: 4.6" (118mm) Length from backplate to center of engine: 1.1" (27.4mm) Width of crankcase below mounting tabs: 1.7" (43mm) Width between mounting tabs: 2.4" (61mm)

Pipe- Length: 12.3" (313mm) Diameter: 2.0" (50mm) at engine attachment point Exhaust Outlet Diameter: 0.20" (5mm) Weight: 7.9oz (225g)

jxs 04/08/11 ir/jxs

– If you need more information, use these O.S. resources –
Click Here: Manufacturer's Product Web Page
Web Site:
Phone: 217-398-8970
  Postal Address:

Click here for Units of Measure Conversion Calculators

Accessories Needed
This is the O.S.Speed .91HZ-R 3D Competition Heli Engine w/PowerBoost Pipe. FEATURES: REQUIRES: 10%-30% nitro fuel w/at least 18% lubricant content, glow starter & field equipment

Accessories for the O.S. 91HZ-R 3D Speed Black w/Powerboost Pipe

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
 LXK129 Great Planes Silicone Fuel Tubing Standard 3'
Qty Discount Available
2.79   In Stock
 LXK134 Great Planes Ultra Precision Fuel Filter
Qty Discount Available
3.79   In Stock
 LXL387 Hobbico 4-Way Wrench w/Plug Storage
Qty Discount Available
4.99   In Stock
Subtotal for this Group of Accessories: 11.57  
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
BizRate Customer Certified (GOLD) Site Shop Now Using PayPal
We accept the following:

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.
Follow Tower Hobbies On