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Tohatsu MD50B2 2-Stroke TLDI Specs
The Tohatsu MD50B2 is a two-stroke three-cylinder in-line gasoline outboard engine. This engine has a 2-stroke low pressure direct injection fuel system, forced water cooling with thermostat, and inductive ignition system. A 42.5 cu.in (697 cc) outboard motor has a cylinder bore of 2.68" (68 mm), piston stroke of 2.52" (64 mm), and maximum power of 50 hp (36.8 kW) at 5150-5850 rpm. The boat motor is equipped with an electric starting system, 3-blades aluminum standard propeller, manual or power trim and tilt, and tiller handle steering system. The fuel tank has a capacity of 6.6 gal (25 liters).
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| General Technical Data |
Engine Model ................ Tohatsu MD50B2
Engine Type ................ 2-stroke three-cylinder gasoline outboard engine
Number of Cylinders ................ 3
Displacement, cu.in (cc) ................ 42.5 (697)
Cylinder Bore, in (mm) ................ 2.68 (68.0)
Piston Stroke, in (mm) ................ 2.52 (64.0)
Maximum Engine Power, hp (kW) ................ 50.0 (36.8)
Maximum Engine Speed, rpm ................ 5150-5850
Idle Speed, rpm ................ 900
Trolling Speed, rpm ................ 800
Compression Ratio ................ 7.2:1
Firing Order ................ 1-2-3
Lubrication System ................ Oil injection
Exhaust System ................ Through hub
Cooling System ................ Water cooling with thermostat
Ignition System ................ Inductive
Starting System ................ Electric starter
| Dimensions and Weight |
Overall Length, in (mm) ................ 44.1 (1120)
Overall Width, in (mm) ................ 15.1 (385)
Overall Height (Short Shaft), in (mm) ................ 48.3 (1225)
Overall Height (Long Shaft), in (mm) ................ 53.3 (1355)
Overall Height (Extra Long Shaft), in (mm) ................ 58.3 (1480)
Transom Height (Short Shaft), in (mm) ................ 15.9 (405)
Transom Height (Long Shaft), in (mm) ................ 20.9 (530)
Transom Height (Extra Long Shaft), in (mm) ................ 25.8 (655)
Outboard Weight (Short Shaft), lbs (kg) ................ 212.5 (96.5)
Outboard Weight (Long Shaft), lbs (kg) ................ 215 (97.5)
Outboard Weight (Extra Long Shaft), lbs (kg) ................ 220 (100.0)
| Fuel System |
Fuel System Type ................ Two stroke low pressure direct injection (TLDI)
Fuel Type ................ Unleaded gasoline (87 or 91 octane minimum)
Fuel Consumption, L/hr ................ 16.5
Fuel Tank Capacity, gal (L) ................ 6.6 (25.0)
| Gear Housing |
Shift System ................ Dog clutch
Gear Shift ................ F-N-R
Gear Type ................ Spiral bevel gear
Gear Ratio ................ 1.85:1
Gear Oil Capacity, qts (L) ................ 0.53 (0.50)
| Mid Section |
Trim System (EFTO) ................ Power Trim and Tilt
Trim System (EFO) ................ Manual Trim and Tilt
Tilt Position (EFTO) ................ 4
Tilt Position (EFO) ................ 6
Transom Height (Short Shaft), in (mm) ................ 15.9 (405)
Transom Height (Long Shaft), in (mm) ................ 20.9 (530)
Transom Height (Extra Long Shaft), in (mm) ................ 25.8 (655)
Steering System ................ Tiller handle
Steering Angle, deg ................ 75
Tilt Angle (Max), deg ................ 80
| Propeller Information |
Diameter, in (mm) ................ 10.9 (278), 11 (279), 11.4 (290), 12.2 (311)
Pitch, in (mm) ................ 9 (229), 11 (279), 12 (305), 13 (330), 14 (356), 15 (381)
Number Of Blade ................ 3
Material ................ Aluminum
| Maintenance Data |
Engine Fuel Type ................ Unleaded 87 or 91 octane minimum
Engine Oil Type ................ Genuine motor oil or recommended one
Engine Oil Capacity, qts (L) ................ 2.1 (2.0)
Gear Lubricant Type ................ Hypoid Gear Oil or API GL5, SAE 80, SAE 90
Gearcase Capacity, qts (L) ................ 0.53 (0.50)
Spark Plug Type ................ NGK IZFR6J or NGK IZFR6Q
Spark Plug Gap, in (mm) ................ 0.031-0.035 (0.8-0.9)
| Service Data |
Cylinder Bore Inside Diameter, in (mm) ................ 2.677-2.679 (68.00-68.05)
Piston to Cylinder Clearance, in (mm) ................ 0.0031-0.0047 (0.08-0.12)
Piston Skirt Diameter, in (mm) ................ 2.674-2.675 (67.92-67.96)
Piston to Piston Pin Clearance, in (mm) ................ 0.0002-0.0005 (0.005-0.013)
Piston Pin Bore Inside Diameter, in (mm) ................ 0.6693-0.6695 (17.001-17.007)
Top Ring End Gap, in (mm) ................ 0.015-0.021 (0.38-0.53)
Second Ring End Gap, in (mm) ................ 0.015-0.021 (0.38-0.53)
Top Ring Side Clearance, in (mm) ................ 0.0016-0.0032 (0.04-0.08)
Second Ring Side Clearance, in (mm) ................ 0.0016-0.0032 (0.04-0.08)
| Service Intervals |
Check Gear Oil ................ Every 50 hours
Check Propeller ................ Every 50 hours
Check Battery ................ Every 100 hours
Check Fuel Filter ................ Every 100 hours
Check Spark Plug ................ Every 100 hours
Check Fuel Line ................ Every 100 hours
Check Anodes ................ Every 100 hours
Check Drive Belt ................ Every 100 hours
Check Air Filter ................ Every 100 hours
Clean Fuel Tank ................ Every 100 hours
Check Cooling System ................ Every 100 hours
Check Water Pump ................ Every 100 hours
Change Gear Oil ................ Every 100 hours
Replace High Pressure Fuel Filter ................ Every 200 hours
Replace Fuel Filter ................ Every 200 hours
Replace Spark Plug ................ Every 200 hours
| Tightening Torques |
Cylinder head bolt, Nm (lb-ft) ................ 32 (23.0)
Crankcase bolt, Nm (lb-ft) ................ 25 (18.0)
Exhaust cover bolt, Nm (lb-ft) ................ 12 (9.0)
Compressor head bolt, Nm (lb-ft) ................ 9 (7.0)
Air box bolt, Nm (lb-ft) ................ 9 (7.0)
Flywheel nut, Nm (lb-ft) ................ 150 (108.0)
Drive pulley nut, Nm (lb-ft) ................ 100 (74.0)
Propeller nut, Nm (lb-ft) ................ 35 (25.0)
Gear case bolt, Nm (lb-ft) ................ 20 (14.0)
Spark plug, Nm (lb-ft) ................ 25 (18.0)
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| Engines Technical Specifications |