O.S. 55AX ABL .55 Airplane Engine w/Muffler

Tower Stock# LXNMD1  •  Manufacturer Stock# 15611
Tech Notices:Notice 1
Notes from our tech department:
This is the O.S. Max .55 AX Aircraft Engine with Muffler.


Same mounting dimensions as the O.S. Max .46 AX
Advanced Bi-Metallic Liner process uses a double layer of plating
material rather than one thick layer. This helps the metal bond to
the cylinder and makes the plating more durable. Also, the plating
process is more consistent, resulting in a more precise fit between
piston and sleeve for better compression and longer life.
Power Box positionable muffler
Angular head design offers increased surface area for better cooling
40J Carburetor with diagonally placed Needle Valve eliminating Remote
Needle Valve placement
Two year limited warranty


O.S. Max 55 AX ABL Aircraft Engine with E-3070 Muffler, 40J
carburetor, 8 glow plug, illustrated instruction manual, 3.5
(90mm) long needle valve extension cable and two 3x35mm muffler


Aircraft blend fuel containing 5-20 Nitromethane with at least 18


Displacement: .545 cu in (8.93cc)
Bore: .906 (23mm)
Stroke: .846 (21.5mm)
Practical RPM: 2,000-17,000
Power Output: 1.75 PS, 1.68 HP16,000 RPM
Weight: 14.29oz (405g) wo muffler
18.52oz (525g) w muffler
Recommended Props: 12x7-8, 13x6-7
Crankshaft thread size:14-28
Distanceremote needle to end of crankshaft: 4.7 (119.4mm)
Distance from center of engine to drive hub: 2.4 (60.4mm)
Distance from center of engine to end of crankshaft: 3.4 (87.6mm)
Distancecrankshaft center to muffler exhaust outlet: 3.9 (100.5mm)
Height from crankcase bottom to top of cylinder head: 3.3 (85.2mm)
Heightcrankshaft center to top of cylinder head: 2.6 (67.4mm)
Width including mounting tabs: 2 (50.8mm)
Width not including mounting tabs: 1.4 (35.6mm)
Width between mounting holes same side: .69 (17.5mm)
Width between mounting holes opposite side: 1.7 (43.2mm)
Diameter of muffler body: 1.5 (38.1mm)
Angle of muffler in relation to engine: 4

High Speed Needle: 2 turns out from fully closed
Low Speed Neelde: 3mm gap between the needle and spray bar at full
throttle (looking down the neck of the carb)


Available Pitts Mufflers include BISG4046.

jxs 92006
updated jpg 71807
updt lmm 32709



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