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| Home / Outboard Engines / Tohatsu Engines / Tohatsu M2.5A2 |
Tohatsu M2.5A2 2-Stroke Specifications
The Tohatsu M2.5A2 is a 2-stroke 1-cylinder forced water-cooled gasoline outboard engine with a rated power of 2.5 hp (1.8 kW) at 3800-5200 rpm. The engine cylinder bore is 1.85" (47 mm) and piston stroke is 1.69" (43 mm). A 4.6 cubic inches (74.5 cc) outboard motor has a carburetor fuel system, starting system with manual starter, flywheel magneto capacitor discharge ignition system, manual tilt and handle tiller steering. The fuel tank capacity is 0.35 gal (1.4 liters). The propeller is made of aluminum and it has three blades.
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| General Technical Data |
Engine Model ................ Tohatsu M2.5A2
Engine Type ................ 2-stroke single-cylinder gasoline outboard engine
Number of Cylinders ................ 1
Displacement, cu.in (cc) ................ 4.6 (74.5)
Cylinder Bore, in (mm) ................ 1.85 (47.0)
Piston Stroke, in (mm) ................ 1.69 (43.0)
Maximum Engine Power, hp (kW) ................ 2.5 (1.8)
Maximum Engine Speed, rpm ................ 3800-5200
Trolling Speed, rpm ................ 1100
Lubrication System ................ Engine oil mixed gasoline
Exhaust System ................ Underwater exhaust
Cooling System ................ Forced water cooling
Ignition System ................ Flywheel Magneto CDI
Starting System ................ Manual
| Dimensions and Weight |
Overall Length, in (mm) ................ 21.7 (550)
Overall Width, in (mm) ................ 13.6 (345)
Overall Height (Short Shaft), in (mm) ................ 37.6 (955)
Overall Height (Long Shaft), in (mm) ................ 42.6 (1080)
Transom Height (Short Shaft), in (mm) ................ 17 (435)
Transom Height (Long Shaft), in (mm) ................ 22 (560)
Outboard Weight (Short Shaft), lbs (kg) ................ 27.5 (12.5)
Outboard Weight (Long Shaft), lbs (kg) ................ 28.6 (13.0)
| Fuel System |
Fuel System Type ................ Carburetor
Fuel Type ................ Unleaded gasoline (87 or 91 octane minimum)
Fuel Consumption, L/hr ................ 0.4
Fuel Tank Capacity, qts (L) ................ 1.47 (1.40)
| Gear Housing |
Gear Shift ................ Forward
Gear Ratio ................ 1.85:1
Gear Oil Capacity, qts (L) ................ 0.10 (0.09)
| Mid Section |
Trim System ................ Manual Trim and Tilt
Trim Position ................ 4
Transom Height (Short Shaft), in (mm) ................ 17 (435)
Transom Height (Long Shaft), in (mm) ................ 22 (560)
Steering System ................ Tiller handle
Tilt Angle (Max), deg ................ 70
| Propeller Information |
Diameter, in (mm) ................ 7.4 (188)
Pitch, in (mm) ................ 5.7 (145), 7 (177)
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 (TCW-III)
Engine Oil and Fuel Ratio ................ Unleaded Gasoline 50. Genuine 2-stroke Engine Oil 1
Gear Lubricant Type ................ Genuine Gear Oil or API GL5, SAE 80, SAE 90
Gearcase Capacity, qts (L) ................ 0.10 (0.09)
Ignition Timing, degrees ................ 20 BTDC
Spark Plug Type ................ NGK BP6HS-10, BPR6HS-10
Spark Plug Gap, in (mm) ................ 0.035-0.039 (0.9-1.0)
| Service Data |
Cylinder Bore Inside Diameter, in (mm) ................ 1.850-1.851 (47.00-47.01)
Piston to Cylinder Clearance, in (mm) ................ 0.0023-0.0035 (0.06-0.09)
Piston Ring End Gap, in (mm) ................ 0.007-0.013 (0.18-0.33)
Piston Ring Side Clearance, in (mm) ................ 0.0004-0.002 (0.01-0.05)
Piston to Piston Pin Clearance, in (mm) ................ 0.0002-0.0006 (0.005-0.016)
Connecting Rod Big End Side Clearance, in (mm) ................ 0.0051-0.0125 (0.13-0.32)
| Service Intervals |
Check Spark Plug ................ Every 50 hours
Check Fuel Line ................ Every 50 hours
Clean Fuel Tank ................ Every 50 hours
Check Anodes ................ Every 50 hours
Check Gear Oil ................ Every 50 hours
Check Propeller ................ Every 50 hours
Check Starter Rope ................ Every 50 hours
Check Cooling System ................ Every 100 hours
Check Water Pump ................ Every 100 hours
Check Carburetor ................ Every 100 hours
Change Gear Oil ................ Every 200 hours
Replace Spark Plug ................ Every 200 hours
| Tightening Torques |
Cylinder head bolt, Nm (lb-ft) ................ 11 (8.2)
Magneto nut, Nm (lb-ft) ................ 44 (32.5)
Stern bracket nut, Nm (lb-ft) ................ 15.5 (11.5)
Emergency stop switch, Nm (lb-ft) ................ 2.5 (1.9)
Spark plug, Nm (lb-ft) ................ 27 (20.0)
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| Engines Technical Specifications |